/* Copyright 2005-2008 MySQL AB, 2008 Sun Microsystems, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* This file is a container for general functionality related to partitioning introduced in MySQL version 5.1. It contains functionality used by all handlers that support partitioning, such as the partitioning handler itself and the NDB handler. The first version was written by Mikael Ronstrom. This version supports RANGE partitioning, LIST partitioning, HASH partitioning and composite partitioning (hereafter called subpartitioning) where each RANGE/LIST partitioning is HASH partitioned. The hash function can either be supplied by the user or by only a list of fields (also called KEY partitioning), where the MySQL server will use an internal hash function. There are quite a few defaults that can be used as well. */ /* Some general useful functions */ #define MYSQL_LEX 1 #include "mysql_priv.h" #include #include #include "my_md5.h" #ifdef WITH_PARTITION_STORAGE_ENGINE #include "ha_partition.h" /* Partition related functions declarations and some static constants; */ const LEX_STRING partition_keywords[]= { { C_STRING_WITH_LEN("HASH") }, { C_STRING_WITH_LEN("RANGE") }, { C_STRING_WITH_LEN("LIST") }, { C_STRING_WITH_LEN("KEY") }, { C_STRING_WITH_LEN("MAXVALUE") }, { C_STRING_WITH_LEN("LINEAR ") } }; static const char *part_str= "PARTITION"; static const char *sub_str= "SUB"; static const char *by_str= "BY"; static const char *space_str= " "; static const char *equal_str= "="; static const char *end_paren_str= ")"; static const char *begin_paren_str= "("; static const char *comma_str= ","; static int get_part_id_charset_func_all(partition_info *part_info, uint32 *part_id, longlong *func_value); static int get_part_id_charset_func_part(partition_info *part_info, uint32 *part_id, longlong *func_value); static int get_part_id_charset_func_subpart(partition_info *part_info, uint32 *part_id, longlong *func_value); static int get_part_part_id_charset_func(partition_info *part_info, uint32 *part_id, longlong *func_value); static int get_subpart_id_charset_func(partition_info *part_info, uint32 *part_id); int get_partition_id_list(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_range(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_hash_nosub(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_key_nosub(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_linear_hash_nosub(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_linear_key_nosub(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_range_sub_hash(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_range_sub_key(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_range_sub_linear_hash(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_range_sub_linear_key(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_list_sub_hash(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_list_sub_key(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_list_sub_linear_hash(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_list_sub_linear_key(partition_info *part_info, uint32 *part_id, longlong *func_value); int get_partition_id_hash_sub(partition_info *part_info, uint32 *part_id); int get_partition_id_key_sub(partition_info *part_info, uint32 *part_id); int get_partition_id_linear_hash_sub(partition_info *part_info, uint32 *part_id); int get_partition_id_linear_key_sub(partition_info *part_info, uint32 *part_id); static uint32 get_next_partition_via_walking(PARTITION_ITERATOR*); static void set_up_range_analysis_info(partition_info *part_info); static uint32 get_next_subpartition_via_walking(PARTITION_ITERATOR*); #endif uint32 get_next_partition_id_range(PARTITION_ITERATOR* part_iter); uint32 get_next_partition_id_list(PARTITION_ITERATOR* part_iter); int get_part_iter_for_interval_via_mapping(partition_info *part_info, bool is_subpart, uchar *min_value, uchar *max_value, uint flags, PARTITION_ITERATOR *part_iter); int get_part_iter_for_interval_via_walking(partition_info *part_info, bool is_subpart, uchar *min_value, uchar *max_value, uint flags, PARTITION_ITERATOR *part_iter); #ifdef WITH_PARTITION_STORAGE_ENGINE /* A support function to check if a name is in a list of strings SYNOPSIS is_name_in_list() name String searched for list_names A list of names searched in RETURN VALUES TRUE String found FALSE String not found */ bool is_name_in_list(char *name, List list_names) { List_iterator names_it(list_names); uint no_names= list_names.elements; uint i= 0; do { char *list_name= names_it++; if (!(my_strcasecmp(system_charset_info, name, list_name))) return TRUE; } while (++i < no_names); return FALSE; } /* Set-up defaults for partitions. SYNOPSIS partition_default_handling() table Table object part_info Partition info to set up is_create_table_ind Is this part of a table creation normalized_path Normalized path name of table and database RETURN VALUES TRUE Error FALSE Success */ bool partition_default_handling(TABLE *table, partition_info *part_info, bool is_create_table_ind, const char *normalized_path) { DBUG_ENTER("partition_default_handling"); if (part_info->use_default_no_partitions) { if (!is_create_table_ind && table->file->get_no_parts(normalized_path, &part_info->no_parts)) { DBUG_RETURN(TRUE); } } else if (part_info->is_sub_partitioned() && part_info->use_default_no_subpartitions) { uint no_parts; if (!is_create_table_ind && (table->file->get_no_parts(normalized_path, &no_parts))) { DBUG_RETURN(TRUE); } DBUG_ASSERT(part_info->no_parts > 0); part_info->no_subparts= no_parts / part_info->no_parts; DBUG_ASSERT((no_parts % part_info->no_parts) == 0); } part_info->set_up_defaults_for_partitioning(table->file, (ulonglong)0, (uint)0); DBUG_RETURN(FALSE); } /* Check that the reorganized table will not have duplicate partitions. SYNOPSIS check_reorganise_list() new_part_info New partition info old_part_info Old partition info list_part_names The list of partition names that will go away and can be reused in the new table. RETURN VALUES TRUE Inacceptable name conflict detected. FALSE New names are OK. DESCRIPTION Can handle that the 'new_part_info' and 'old_part_info' the same in which case it checks that the list of names in the partitions doesn't contain any duplicated names. */ bool check_reorganise_list(partition_info *new_part_info, partition_info *old_part_info, List list_part_names) { uint new_count, old_count; uint no_new_parts= new_part_info->partitions.elements; uint no_old_parts= old_part_info->partitions.elements; List_iterator new_parts_it(new_part_info->partitions); bool same_part_info= (new_part_info == old_part_info); DBUG_ENTER("check_reorganise_list"); new_count= 0; do { List_iterator old_parts_it(old_part_info->partitions); char *new_name= (new_parts_it++)->partition_name; new_count++; old_count= 0; do { char *old_name= (old_parts_it++)->partition_name; old_count++; if (same_part_info && old_count == new_count) break; if (!(my_strcasecmp(system_charset_info, old_name, new_name))) { if (!is_name_in_list(old_name, list_part_names)) DBUG_RETURN(TRUE); } } while (old_count < no_old_parts); } while (new_count < no_new_parts); DBUG_RETURN(FALSE); } /* A useful routine used by update_row for partition handlers to calculate the partition ids of the old and the new record. SYNOPSIS get_part_for_update() old_data Buffer of old record new_data Buffer of new record rec0 Reference to table->record[0] part_info Reference to partition information out:old_part_id The returned partition id of old record out:new_part_id The returned partition id of new record RETURN VALUE 0 Success > 0 Error code */ int get_parts_for_update(const uchar *old_data, uchar *new_data, const uchar *rec0, partition_info *part_info, uint32 *old_part_id, uint32 *new_part_id, longlong *new_func_value) { Field **part_field_array= part_info->full_part_field_array; int error; longlong old_func_value; DBUG_ENTER("get_parts_for_update"); DBUG_ASSERT(new_data == rec0); set_field_ptr(part_field_array, old_data, rec0); error= part_info->get_partition_id(part_info, old_part_id, &old_func_value); set_field_ptr(part_field_array, rec0, old_data); if (unlikely(error)) // Should never happen { DBUG_ASSERT(0); DBUG_RETURN(error); } #ifdef NOT_NEEDED if (new_data == rec0) #endif { if (unlikely(error= part_info->get_partition_id(part_info, new_part_id, new_func_value))) { DBUG_RETURN(error); } } #ifdef NOT_NEEDED else { /* This branch should never execute but it is written anyways for future use. It will be tested by ensuring that the above condition is false in one test situation before pushing the code. */ set_field_ptr(part_field_array, new_data, rec0); error= part_info->get_partition_id(part_info, new_part_id, new_func_value); set_field_ptr(part_field_array, rec0, new_data); if (unlikely(error)) { DBUG_RETURN(error); } } #endif DBUG_RETURN(0); } /* A useful routine used by delete_row for partition handlers to calculate the partition id. SYNOPSIS get_part_for_delete() buf Buffer of old record rec0 Reference to table->record[0] part_info Reference to partition information out:part_id The returned partition id to delete from RETURN VALUE 0 Success > 0 Error code DESCRIPTION Dependent on whether buf is not record[0] we need to prepare the fields. Then we call the function pointer get_partition_id to calculate the partition id. */ int get_part_for_delete(const uchar *buf, const uchar *rec0, partition_info *part_info, uint32 *part_id) { int error; longlong func_value; DBUG_ENTER("get_part_for_delete"); if (likely(buf == rec0)) { if (unlikely((error= part_info->get_partition_id(part_info, part_id, &func_value)))) { DBUG_RETURN(error); } DBUG_PRINT("info", ("Delete from partition %d", *part_id)); } else { Field **part_field_array= part_info->full_part_field_array; set_field_ptr(part_field_array, buf, rec0); error= part_info->get_partition_id(part_info, part_id, &func_value); set_field_ptr(part_field_array, rec0, buf); if (unlikely(error)) { DBUG_RETURN(error); } DBUG_PRINT("info", ("Delete from partition %d (path2)", *part_id)); } DBUG_RETURN(0); } /* This method is used to set-up both partition and subpartitioning field array and used for all types of partitioning. It is part of the logic around fix_partition_func. SYNOPSIS set_up_field_array() table TABLE object for which partition fields are set-up sub_part Is the table subpartitioned as well RETURN VALUE TRUE Error, some field didn't meet requirements FALSE Ok, partition field array set-up DESCRIPTION A great number of functions below here is part of the fix_partition_func method. It is used to set up the partition structures for execution from openfrm. It is called at the end of the openfrm when the table struct has been set-up apart from the partition information. It involves: 1) Setting arrays of fields for the partition functions. 2) Setting up binary search array for LIST partitioning 3) Setting up array for binary search for RANGE partitioning 4) Setting up key_map's to assist in quick evaluation whether one can deduce anything from a given index of what partition to use 5) Checking whether a set of partitions can be derived from a range on a field in the partition function. As part of doing this there is also a great number of error controls. This is actually the place where most of the things are checked for partition information when creating a table. Things that are checked includes 1) All fields of partition function in Primary keys and unique indexes (if not supported) Create an array of partition fields (NULL terminated). Before this method is called fix_fields or find_table_in_sef has been called to set GET_FIXED_FIELDS_FLAG on all fields that are part of the partition function. */ static bool set_up_field_array(TABLE *table, bool is_sub_part) { Field **ptr, *field, **field_array; uint no_fields= 0; uint size_field_array; uint i= 0; partition_info *part_info= table->part_info; int result= FALSE; DBUG_ENTER("set_up_field_array"); ptr= table->field; while ((field= *(ptr++))) { if (field->flags & GET_FIXED_FIELDS_FLAG) no_fields++; } if (no_fields == 0) { /* We are using hidden key as partitioning field */ DBUG_ASSERT(!is_sub_part); DBUG_RETURN(result); } size_field_array= (no_fields+1)*sizeof(Field*); field_array= (Field**)sql_alloc(size_field_array); if (unlikely(!field_array)) { mem_alloc_error(size_field_array); result= TRUE; } ptr= table->field; while ((field= *(ptr++))) { if (field->flags & GET_FIXED_FIELDS_FLAG) { field->flags&= ~GET_FIXED_FIELDS_FLAG; field->flags|= FIELD_IN_PART_FUNC_FLAG; if (likely(!result)) { field_array[i++]= field; /* We check that the fields are proper. It is required for each field in a partition function to: 1) Not be a BLOB of any type A BLOB takes too long time to evaluate so we don't want it for performance reasons. */ if (unlikely(field->flags & BLOB_FLAG)) { my_error(ER_BLOB_FIELD_IN_PART_FUNC_ERROR, MYF(0)); result= TRUE; } } } } field_array[no_fields]= 0; if (!is_sub_part) { part_info->part_field_array= field_array; part_info->no_part_fields= no_fields; } else { part_info->subpart_field_array= field_array; part_info->no_subpart_fields= no_fields; } DBUG_RETURN(result); } /* Create a field array including all fields of both the partitioning and the subpartitioning functions. SYNOPSIS create_full_part_field_array() thd Thread handle table TABLE object for which partition fields are set-up part_info Reference to partitioning data structure RETURN VALUE TRUE Memory allocation of field array failed FALSE Ok DESCRIPTION If there is no subpartitioning then the same array is used as for the partitioning. Otherwise a new array is built up using the flag FIELD_IN_PART_FUNC in the field object. This function is called from fix_partition_func */ static bool create_full_part_field_array(THD *thd, TABLE *table, partition_info *part_info) { bool result= FALSE; Field **ptr; my_bitmap_map *bitmap_buf; DBUG_ENTER("create_full_part_field_array"); if (!part_info->is_sub_partitioned()) { part_info->full_part_field_array= part_info->part_field_array; part_info->no_full_part_fields= part_info->no_part_fields; } else { Field *field, **field_array; uint no_part_fields=0, size_field_array; ptr= table->field; while ((field= *(ptr++))) { if (field->flags & FIELD_IN_PART_FUNC_FLAG) no_part_fields++; } size_field_array= (no_part_fields+1)*sizeof(Field*); field_array= (Field**)sql_alloc(size_field_array); if (unlikely(!field_array)) { mem_alloc_error(size_field_array); result= TRUE; goto end; } no_part_fields= 0; ptr= table->field; while ((field= *(ptr++))) { if (field->flags & FIELD_IN_PART_FUNC_FLAG) field_array[no_part_fields++]= field; } field_array[no_part_fields]=0; part_info->full_part_field_array= field_array; part_info->no_full_part_fields= no_part_fields; } /* Initialize the set of all fields used in partition and subpartition expression. Required for testing of partition fields in write_set when updating. We need to set all bits in read_set because the row may need to be inserted in a different [sub]partition. */ if (!(bitmap_buf= (my_bitmap_map*) thd->alloc(bitmap_buffer_size(table->s->fields)))) { mem_alloc_error(bitmap_buffer_size(table->s->fields)); result= TRUE; goto end; } if (bitmap_init(&part_info->full_part_field_set, bitmap_buf, table->s->fields, FALSE)) { mem_alloc_error(table->s->fields); result= TRUE; goto end; } /* full_part_field_array may be NULL if storage engine supports native partitioning. */ if ((ptr= part_info->full_part_field_array)) for (; *ptr; ptr++) bitmap_set_bit(&part_info->full_part_field_set, (*ptr)->field_index); end: DBUG_RETURN(result); } /* Clear flag GET_FIXED_FIELDS_FLAG in all fields of a key previously set by set_indicator_in_key_fields (always used in pairs). SYNOPSIS clear_indicator_in_key_fields() key_info Reference to find the key fields RETURN VALUE NONE DESCRIPTION These support routines is used to set/reset an indicator of all fields in a certain key. It is used in conjunction with another support routine that traverse all fields in the PF to find if all or some fields in the PF is part of the key. This is used to check primary keys and unique keys involve all fields in PF (unless supported) and to derive the key_map's used to quickly decide whether the index can be used to derive which partitions are needed to scan. */ static void clear_indicator_in_key_fields(KEY *key_info) { KEY_PART_INFO *key_part; uint key_parts= key_info->key_parts, i; for (i= 0, key_part=key_info->key_part; i < key_parts; i++, key_part++) key_part->field->flags&= (~GET_FIXED_FIELDS_FLAG); } /* Set flag GET_FIXED_FIELDS_FLAG in all fields of a key. SYNOPSIS set_indicator_in_key_fields key_info Reference to find the key fields RETURN VALUE NONE */ static void set_indicator_in_key_fields(KEY *key_info) { KEY_PART_INFO *key_part; uint key_parts= key_info->key_parts, i; for (i= 0, key_part=key_info->key_part; i < key_parts; i++, key_part++) key_part->field->flags|= GET_FIXED_FIELDS_FLAG; } /* Check if all or some fields in partition field array is part of a key previously used to tag key fields. SYNOPSIS check_fields_in_PF() ptr Partition field array out:all_fields Is all fields of partition field array used in key out:some_fields Is some fields of partition field array used in key RETURN VALUE all_fields, some_fields */ static void check_fields_in_PF(Field **ptr, bool *all_fields, bool *some_fields) { DBUG_ENTER("check_fields_in_PF"); *all_fields= TRUE; *some_fields= FALSE; if ((!ptr) || !(*ptr)) { *all_fields= FALSE; DBUG_VOID_RETURN; } do { /* Check if the field of the PF is part of the current key investigated */ if ((*ptr)->flags & GET_FIXED_FIELDS_FLAG) *some_fields= TRUE; else *all_fields= FALSE; } while (*(++ptr)); DBUG_VOID_RETURN; } /* Clear flag GET_FIXED_FIELDS_FLAG in all fields of the table. This routine is used for error handling purposes. SYNOPSIS clear_field_flag() table TABLE object for which partition fields are set-up RETURN VALUE NONE */ static void clear_field_flag(TABLE *table) { Field **ptr; DBUG_ENTER("clear_field_flag"); for (ptr= table->field; *ptr; ptr++) (*ptr)->flags&= (~GET_FIXED_FIELDS_FLAG); DBUG_VOID_RETURN; } /* find_field_in_table_sef finds the field given its name. All fields get GET_FIXED_FIELDS_FLAG set. SYNOPSIS handle_list_of_fields() it A list of field names for the partition function table TABLE object for which partition fields are set-up part_info Reference to partitioning data structure sub_part Is the table subpartitioned as well RETURN VALUE TRUE Fields in list of fields not part of table FALSE All fields ok and array created DESCRIPTION This routine sets-up the partition field array for KEY partitioning, it also verifies that all fields in the list of fields is actually a part of the table. */ static bool handle_list_of_fields(List_iterator it, TABLE *table, partition_info *part_info, bool is_sub_part) { Field *field; bool result; char *field_name; bool is_list_empty= TRUE; DBUG_ENTER("handle_list_of_fields"); while ((field_name= it++)) { is_list_empty= FALSE; field= find_field_in_table_sef(table, field_name); if (likely(field != 0)) field->flags|= GET_FIXED_FIELDS_FLAG; else { my_error(ER_FIELD_NOT_FOUND_PART_ERROR, MYF(0)); clear_field_flag(table); result= TRUE; goto end; } } if (is_list_empty) { uint primary_key= table->s->primary_key; if (primary_key != MAX_KEY) { uint no_key_parts= table->key_info[primary_key].key_parts, i; /* In the case of an empty list we use primary key as partition key. */ for (i= 0; i < no_key_parts; i++) { Field *field= table->key_info[primary_key].key_part[i].field; field->flags|= GET_FIXED_FIELDS_FLAG; } } else { if (table->s->db_type()->partition_flags && (table->s->db_type()->partition_flags() & HA_USE_AUTO_PARTITION) && (table->s->db_type()->partition_flags() & HA_CAN_PARTITION)) { /* This engine can handle automatic partitioning and there is no primary key. In this case we rely on that the engine handles partitioning based on a hidden key. Thus we allocate no array for partitioning fields. */ DBUG_RETURN(FALSE); } else { my_error(ER_FIELD_NOT_FOUND_PART_ERROR, MYF(0)); DBUG_RETURN(TRUE); } } } result= set_up_field_array(table, is_sub_part); end: DBUG_RETURN(result); } /* Support function to check if all VALUES * (expression) is of the right sign (no signed constants when unsigned partition function) SYNOPSIS check_signed_flag() part_info Partition info object RETURN VALUES 0 No errors due to sign errors >0 Sign error */ int check_signed_flag(partition_info *part_info) { int error= 0; uint i= 0; if (part_info->part_type != HASH_PARTITION && part_info->part_expr->unsigned_flag) { List_iterator part_it(part_info->partitions); do { partition_element *part_elem= part_it++; if (part_elem->signed_flag) { my_error(ER_PARTITION_CONST_DOMAIN_ERROR, MYF(0)); error= ER_PARTITION_CONST_DOMAIN_ERROR; break; } } while (++i < part_info->no_parts); } return error; } /* The function uses a new feature in fix_fields where the flag GET_FIXED_FIELDS_FLAG is set for all fields in the item tree. This field must always be reset before returning from the function since it is used for other purposes as well. SYNOPSIS fix_fields_part_func() thd The thread object func_expr The item tree reference of the partition function table The table object part_info Reference to partitioning data structure is_sub_part Is the table subpartitioned as well is_field_to_be_setup Flag if we are to set-up field arrays RETURN VALUE TRUE An error occurred, something was wrong with the partition function. FALSE Ok, a partition field array was created DESCRIPTION This function is used to build an array of partition fields for the partitioning function and subpartitioning function. The partitioning function is an item tree that must reference at least one field in the table. This is checked first in the parser that the function doesn't contain non-cacheable parts (like a random function) and by checking here that the function isn't a constant function. Calculate the number of fields in the partition function. Use it allocate memory for array of Field pointers. Initialise array of field pointers. Use information set when calling fix_fields and reset it immediately after. The get_fields_in_item_tree activates setting of bit in flags on the field object. */ bool fix_fields_part_func(THD *thd, Item* func_expr, TABLE *table, bool is_sub_part, bool is_field_to_be_setup) { partition_info *part_info= table->part_info; uint dir_length, home_dir_length; bool result= TRUE; TABLE_LIST tables; TABLE_LIST *save_table_list, *save_first_table, *save_last_table; int error; Name_resolution_context *context; const char *save_where; char* db_name; char db_name_string[FN_REFLEN]; bool save_use_only_table_context; DBUG_ENTER("fix_fields_part_func"); if (part_info->fixed) { if (!(is_sub_part || (error= check_signed_flag(part_info)))) result= FALSE; goto end; } /* Set-up the TABLE_LIST object to be a list with a single table Set the object to zero to create NULL pointers and set alias and real name to table name and get database name from file name. */ bzero((void*)&tables, sizeof(TABLE_LIST)); tables.alias= tables.table_name= (char*) table->s->table_name.str; tables.table= table; tables.next_local= 0; tables.next_name_resolution_table= 0; strmov(db_name_string, table->s->normalized_path.str); dir_length= dirname_length(db_name_string); db_name_string[dir_length - 1]= 0; home_dir_length= dirname_length(db_name_string); db_name= &db_name_string[home_dir_length]; tables.db= db_name; context= thd->lex->current_context(); table->map= 1; //To ensure correct calculation of const item table->get_fields_in_item_tree= TRUE; save_table_list= context->table_list; save_first_table= context->first_name_resolution_table; save_last_table= context->last_name_resolution_table; context->table_list= &tables; context->first_name_resolution_table= &tables; context->last_name_resolution_table= NULL; func_expr->walk(&Item::change_context_processor, 0, (uchar*) context); save_where= thd->where; thd->where= "partition function"; /* In execution we must avoid the use of thd->change_item_tree since we might release memory before statement is completed. We do this by temporarily setting the stmt_arena->mem_root to be the mem_root of the table object, this also ensures that any memory allocated during fix_fields will not be released at end of execution of this statement. Thus the item tree will remain valid also in subsequent executions of this table object. We do however not at the moment support allocations during execution of val_int so any item class that does this during val_int must be disallowed as partition function. SEE Bug #21658 */ /* This is a tricky call to prepare for since it can have a large number of interesting side effects, both desirable and undesirable. */ save_use_only_table_context= thd->lex->use_only_table_context; thd->lex->use_only_table_context= TRUE; error= func_expr->fix_fields(thd, (Item**)0); thd->lex->use_only_table_context= save_use_only_table_context; context->table_list= save_table_list; context->first_name_resolution_table= save_first_table; context->last_name_resolution_table= save_last_table; if (unlikely(error)) { DBUG_PRINT("info", ("Field in partition function not part of table")); if (is_field_to_be_setup) clear_field_flag(table); goto end; } thd->where= save_where; if (unlikely(func_expr->const_item())) { my_error(ER_CONST_EXPR_IN_PARTITION_FUNC_ERROR, MYF(0)); clear_field_flag(table); goto end; } if ((!is_sub_part) && (error= check_signed_flag(part_info))) goto end; result= FALSE; if (is_field_to_be_setup) result= set_up_field_array(table, is_sub_part); if (!is_sub_part) part_info->fixed= TRUE; end: table->get_fields_in_item_tree= FALSE; table->map= 0; //Restore old value DBUG_RETURN(result); } /* Check that the primary key contains all partition fields if defined SYNOPSIS check_primary_key() table TABLE object for which partition fields are set-up RETURN VALUES TRUE Not all fields in partitioning function was part of primary key FALSE Ok, all fields of partitioning function were part of primary key DESCRIPTION This function verifies that if there is a primary key that it contains all the fields of the partition function. This is a temporary limitation that will hopefully be removed after a while. */ static bool check_primary_key(TABLE *table) { uint primary_key= table->s->primary_key; bool all_fields, some_fields; bool result= FALSE; DBUG_ENTER("check_primary_key"); if (primary_key < MAX_KEY) { set_indicator_in_key_fields(table->key_info+primary_key); check_fields_in_PF(table->part_info->full_part_field_array, &all_fields, &some_fields); clear_indicator_in_key_fields(table->key_info+primary_key); if (unlikely(!all_fields)) { my_error(ER_UNIQUE_KEY_NEED_ALL_FIELDS_IN_PF,MYF(0),"PRIMARY KEY"); result= TRUE; } } DBUG_RETURN(result); } /* Check that unique keys contains all partition fields SYNOPSIS check_unique_keys() table TABLE object for which partition fields are set-up RETURN VALUES TRUE Not all fields in partitioning function was part of all unique keys FALSE Ok, all fields of partitioning function were part of unique keys DESCRIPTION This function verifies that if there is a unique index that it contains all the fields of the partition function. This is a temporary limitation that will hopefully be removed after a while. */ static bool check_unique_keys(TABLE *table) { bool all_fields, some_fields; bool result= FALSE; uint keys= table->s->keys; uint i; DBUG_ENTER("check_unique_keys"); for (i= 0; i < keys; i++) { if (table->key_info[i].flags & HA_NOSAME) //Unique index { set_indicator_in_key_fields(table->key_info+i); check_fields_in_PF(table->part_info->full_part_field_array, &all_fields, &some_fields); clear_indicator_in_key_fields(table->key_info+i); if (unlikely(!all_fields)) { my_error(ER_UNIQUE_KEY_NEED_ALL_FIELDS_IN_PF,MYF(0),"UNIQUE INDEX"); result= TRUE; break; } } } DBUG_RETURN(result); } /* An important optimisation is whether a range on a field can select a subset of the partitions. A prerequisite for this to happen is that the PF is a growing function OR a shrinking function. This can never happen for a multi-dimensional PF. Thus this can only happen with PF with at most one field involved in the PF. The idea is that if the function is a growing function and you know that the field of the PF is 4 <= A <= 6 then we can convert this to a range in the PF instead by setting the range to PF(4) <= PF(A) <= PF(6). In the case of RANGE PARTITIONING and LIST PARTITIONING this can be used to calculate a set of partitions rather than scanning all of them. Thus the following prerequisites are there to check if sets of partitions can be found. 1) Only possible for RANGE and LIST partitioning (not for subpartitioning) 2) Only possible if PF only contains 1 field 3) Possible if PF is a growing function of the field 4) Possible if PF is a shrinking function of the field OBSERVATION: 1) IF f1(A) is a growing function AND f2(A) is a growing function THEN f1(A) + f2(A) is a growing function f1(A) * f2(A) is a growing function if f1(A) >= 0 and f2(A) >= 0 2) IF f1(A) is a growing function and f2(A) is a shrinking function THEN f1(A) / f2(A) is a growing function if f1(A) >= 0 and f2(A) > 0 3) IF A is a growing function then a function f(A) that removes the least significant portion of A is a growing function E.g. DATE(datetime) is a growing function MONTH(datetime) is not a growing/shrinking function 4) IF f1(A) is a growing function and f2(A) is a growing function THEN f1(f2(A)) and f2(f1(A)) are also growing functions 5) IF f1(A) is a shrinking function and f2(A) is a growing function THEN f1(f2(A)) is a shrinking function and f2(f1(A)) is a shrinking function 6) f1(A) = A is a growing function 7) f1(A) = A*a + b (where a and b are constants) is a growing function By analysing the item tree of the PF we can use these deducements and derive whether the PF is a growing function or a shrinking function or neither of it. If the PF is range capable then a flag is set on the table object indicating this to notify that we can use also ranges on the field of the PF to deduce a set of partitions if the fields of the PF were not all fully bound. SYNOPSIS check_range_capable_PF() table TABLE object for which partition fields are set-up DESCRIPTION Support for this is not implemented yet. */ void check_range_capable_PF(TABLE *table) { DBUG_ENTER("check_range_capable_PF"); DBUG_VOID_RETURN; } /* Set up partition bitmap SYNOPSIS set_up_partition_bitmap() thd Thread object part_info Reference to partitioning data structure RETURN VALUE TRUE Memory allocation failure FALSE Success DESCRIPTION Allocate memory for bitmap of the partitioned table and initialise it. */ static bool set_up_partition_bitmap(THD *thd, partition_info *part_info) { uint32 *bitmap_buf; uint bitmap_bits= part_info->no_subparts? (part_info->no_subparts* part_info->no_parts): part_info->no_parts; uint bitmap_bytes= bitmap_buffer_size(bitmap_bits); DBUG_ENTER("set_up_partition_bitmap"); if (!(bitmap_buf= (uint32*)thd->alloc(bitmap_bytes))) { mem_alloc_error(bitmap_bytes); DBUG_RETURN(TRUE); } bitmap_init(&part_info->used_partitions, bitmap_buf, bitmap_bytes*8, FALSE); bitmap_set_all(&part_info->used_partitions); DBUG_RETURN(FALSE); } /* Set up partition key maps SYNOPSIS set_up_partition_key_maps() table TABLE object for which partition fields are set-up part_info Reference to partitioning data structure RETURN VALUES None DESCRIPTION This function sets up a couple of key maps to be able to quickly check if an index ever can be used to deduce the partition fields or even a part of the fields of the partition function. We set up the following key_map's. PF = Partition Function 1) All fields of the PF is set even by equal on the first fields in the key 2) All fields of the PF is set if all fields of the key is set 3) At least one field in the PF is set if all fields is set 4) At least one field in the PF is part of the key */ static void set_up_partition_key_maps(TABLE *table, partition_info *part_info) { uint keys= table->s->keys; uint i; bool all_fields, some_fields; DBUG_ENTER("set_up_partition_key_maps"); part_info->all_fields_in_PF.clear_all(); part_info->all_fields_in_PPF.clear_all(); part_info->all_fields_in_SPF.clear_all(); part_info->some_fields_in_PF.clear_all(); for (i= 0; i < keys; i++) { set_indicator_in_key_fields(table->key_info+i); check_fields_in_PF(part_info->full_part_field_array, &all_fields, &some_fields); if (all_fields) part_info->all_fields_in_PF.set_bit(i); if (some_fields) part_info->some_fields_in_PF.set_bit(i); if (part_info->is_sub_partitioned()) { check_fields_in_PF(part_info->part_field_array, &all_fields, &some_fields); if (all_fields) part_info->all_fields_in_PPF.set_bit(i); check_fields_in_PF(part_info->subpart_field_array, &all_fields, &some_fields); if (all_fields) part_info->all_fields_in_SPF.set_bit(i); } clear_indicator_in_key_fields(table->key_info+i); } DBUG_VOID_RETURN; } /* Set up function pointers for partition function SYNOPSIS set_up_partition_func_pointers() part_info Reference to partitioning data structure RETURN VALUE NONE DESCRIPTION Set-up all function pointers for calculation of partition id, subpartition id and the upper part in subpartitioning. This is to speed up execution of get_partition_id which is executed once every record to be written and deleted and twice for updates. */ static void set_up_partition_func_pointers(partition_info *part_info) { DBUG_ENTER("set_up_partition_func_pointers"); if (part_info->is_sub_partitioned()) { if (part_info->part_type == RANGE_PARTITION) { part_info->get_part_partition_id= get_partition_id_range; if (part_info->list_of_subpart_fields) { if (part_info->linear_hash_ind) { part_info->get_partition_id= get_partition_id_range_sub_linear_key; part_info->get_subpartition_id= get_partition_id_linear_key_sub; } else { part_info->get_partition_id= get_partition_id_range_sub_key; part_info->get_subpartition_id= get_partition_id_key_sub; } } else { if (part_info->linear_hash_ind) { part_info->get_partition_id= get_partition_id_range_sub_linear_hash; part_info->get_subpartition_id= get_partition_id_linear_hash_sub; } else { part_info->get_partition_id= get_partition_id_range_sub_hash; part_info->get_subpartition_id= get_partition_id_hash_sub; } } } else /* LIST Partitioning */ { part_info->get_part_partition_id= get_partition_id_list; if (part_info->list_of_subpart_fields) { if (part_info->linear_hash_ind) { part_info->get_partition_id= get_partition_id_list_sub_linear_key; part_info->get_subpartition_id= get_partition_id_linear_key_sub; } else { part_info->get_partition_id= get_partition_id_list_sub_key; part_info->get_subpartition_id= get_partition_id_key_sub; } } else { if (part_info->linear_hash_ind) { part_info->get_partition_id= get_partition_id_list_sub_linear_hash; part_info->get_subpartition_id= get_partition_id_linear_hash_sub; } else { part_info->get_partition_id= get_partition_id_list_sub_hash; part_info->get_subpartition_id= get_partition_id_hash_sub; } } } } else /* No subpartitioning */ { part_info->get_part_partition_id= NULL; part_info->get_subpartition_id= NULL; if (part_info->part_type == RANGE_PARTITION) part_info->get_partition_id= get_partition_id_range; else if (part_info->part_type == LIST_PARTITION) part_info->get_partition_id= get_partition_id_list; else /* HASH partitioning */ { if (part_info->list_of_part_fields) { if (part_info->linear_hash_ind) part_info->get_partition_id= get_partition_id_linear_key_nosub; else part_info->get_partition_id= get_partition_id_key_nosub; } else { if (part_info->linear_hash_ind) part_info->get_partition_id= get_partition_id_linear_hash_nosub; else part_info->get_partition_id= get_partition_id_hash_nosub; } } } if (part_info->full_part_charset_field_array) { DBUG_ASSERT(part_info->get_partition_id); part_info->get_partition_id_charset= part_info->get_partition_id; if (part_info->part_charset_field_array && part_info->subpart_charset_field_array) part_info->get_partition_id= get_part_id_charset_func_all; else if (part_info->part_charset_field_array) part_info->get_partition_id= get_part_id_charset_func_part; else part_info->get_partition_id= get_part_id_charset_func_subpart; } if (part_info->part_charset_field_array && part_info->is_sub_partitioned()) { DBUG_ASSERT(part_info->get_part_partition_id); part_info->get_part_partition_id_charset= part_info->get_part_partition_id; part_info->get_part_partition_id= get_part_part_id_charset_func; } if (part_info->subpart_charset_field_array) { DBUG_ASSERT(part_info->get_subpartition_id); part_info->get_subpartition_id_charset= part_info->get_subpartition_id; part_info->get_subpartition_id= get_subpart_id_charset_func; } DBUG_VOID_RETURN; } /* For linear hashing we need a mask which is on the form 2**n - 1 where 2**n >= no_parts. Thus if no_parts is 6 then mask is 2**3 - 1 = 8 - 1 = 7. SYNOPSIS set_linear_hash_mask() part_info Reference to partitioning data structure no_parts Number of parts in linear hash partitioning RETURN VALUE NONE */ void set_linear_hash_mask(partition_info *part_info, uint no_parts) { uint mask; for (mask= 1; mask < no_parts; mask<<=1) ; part_info->linear_hash_mask= mask - 1; } /* This function calculates the partition id provided the result of the hash function using linear hashing parameters, mask and number of partitions. SYNOPSIS get_part_id_from_linear_hash() hash_value Hash value calculated by HASH function or KEY function mask Mask calculated previously by set_linear_hash_mask no_parts Number of partitions in HASH partitioned part RETURN VALUE part_id The calculated partition identity (starting at 0) DESCRIPTION The partition is calculated according to the theory of linear hashing. See e.g. Linear hashing: a new tool for file and table addressing, Reprinted from VLDB-80 in Readings Database Systems, 2nd ed, M. Stonebraker (ed.), Morgan Kaufmann 1994. */ static uint32 get_part_id_from_linear_hash(longlong hash_value, uint mask, uint no_parts) { uint32 part_id= (uint32)(hash_value & mask); if (part_id >= no_parts) { uint new_mask= ((mask + 1) >> 1) - 1; part_id= (uint32)(hash_value & new_mask); } return part_id; } /* Check if a particular field is in need of character set handling for partition functions. SYNOPSIS field_is_partition_charset() field The field to check RETURN VALUES FALSE Not in need of character set handling TRUE In need of character set handling */ bool field_is_partition_charset(Field *field) { if (!(field->type() == MYSQL_TYPE_STRING) && !(field->type() == MYSQL_TYPE_VARCHAR)) return FALSE; { CHARSET_INFO *cs= ((Field_str*)field)->charset(); if (!(field->type() == MYSQL_TYPE_STRING) || !(cs->state & MY_CS_BINSORT)) return TRUE; return FALSE; } } /* Check that partition function doesn't contain any forbidden character sets and collations. SYNOPSIS check_part_func_fields() ptr Array of Field pointers ok_with_charsets Will we report allowed charset fields as ok RETURN VALUES FALSE Success TRUE Error DESCRIPTION We will check in this routine that the fields of the partition functions do not contain unallowed parts. It can also be used to check if there are fields that require special care by calling my_strnxfrm before calling the functions to calculate partition id. */ bool check_part_func_fields(Field **ptr, bool ok_with_charsets) { Field *field; DBUG_ENTER("check_part_func_fields"); while ((field= *(ptr++))) { /* For CHAR/VARCHAR fields we need to take special precautions. Binary collation with CHAR is automatically supported. Other types need some kind of standardisation function handling */ if (field_is_partition_charset(field)) { CHARSET_INFO *cs= ((Field_str*)field)->charset(); if (!ok_with_charsets || cs->mbmaxlen > 1 || cs->strxfrm_multiply > 1) { DBUG_RETURN(TRUE); } } } DBUG_RETURN(FALSE); } /* fix partition functions SYNOPSIS fix_partition_func() thd The thread object table TABLE object for which partition fields are set-up is_create_table_ind Indicator of whether openfrm was called as part of CREATE or ALTER TABLE RETURN VALUE TRUE Error FALSE Success DESCRIPTION The name parameter contains the full table name and is used to get the database name of the table which is used to set-up a correct TABLE_LIST object for use in fix_fields. NOTES This function is called as part of opening the table by opening the .frm file. It is a part of CREATE TABLE to do this so it is quite permissible that errors due to erroneus syntax isn't found until we come here. If the user has used a non-existing field in the table is one such example of an error that is not discovered until here. */ bool fix_partition_func(THD *thd, TABLE *table, bool is_create_table_ind) { bool result= TRUE; partition_info *part_info= table->part_info; enum_mark_columns save_mark_used_columns= thd->mark_used_columns; DBUG_ENTER("fix_partition_func"); if (part_info->fixed) { DBUG_RETURN(FALSE); } thd->mark_used_columns= MARK_COLUMNS_NONE; DBUG_PRINT("info", ("thd->mark_used_columns: %d", thd->mark_used_columns)); if (!is_create_table_ind || thd->lex->sql_command != SQLCOM_CREATE_TABLE) { if (partition_default_handling(table, part_info, is_create_table_ind, table->s->normalized_path.str)) { DBUG_RETURN(TRUE); } } if (part_info->is_sub_partitioned()) { DBUG_ASSERT(part_info->subpart_type == HASH_PARTITION); /* Subpartition is defined. We need to verify that subpartitioning function is correct. */ if (part_info->linear_hash_ind) set_linear_hash_mask(part_info, part_info->no_subparts); if (part_info->list_of_subpart_fields) { List_iterator it(part_info->subpart_field_list); if (unlikely(handle_list_of_fields(it, table, part_info, TRUE))) goto end; } else { if (unlikely(fix_fields_part_func(thd, part_info->subpart_expr, table, TRUE, TRUE))) goto end; if (unlikely(part_info->subpart_expr->result_type() != INT_RESULT)) { my_error(ER_PARTITION_FUNC_NOT_ALLOWED_ERROR, MYF(0), "SUBPARTITION"); goto end; } } } DBUG_ASSERT(part_info->part_type != NOT_A_PARTITION); /* Partition is defined. We need to verify that partitioning function is correct. */ if (part_info->part_type == HASH_PARTITION) { if (part_info->linear_hash_ind) set_linear_hash_mask(part_info, part_info->no_parts); if (part_info->list_of_part_fields) { List_iterator it(part_info->part_field_list); if (unlikely(handle_list_of_fields(it, table, part_info, FALSE))) goto end; } else { if (unlikely(fix_fields_part_func(thd, part_info->part_expr, table, FALSE, TRUE))) goto end; if (unlikely(part_info->part_expr->result_type() != INT_RESULT)) { my_error(ER_PARTITION_FUNC_NOT_ALLOWED_ERROR, MYF(0), part_str); goto end; } part_info->part_result_type= INT_RESULT; } } else { const char *error_str; if (unlikely(fix_fields_part_func(thd, part_info->part_expr, table, FALSE, TRUE))) goto end; if (part_info->part_type == RANGE_PARTITION) { error_str= partition_keywords[PKW_RANGE].str; if (unlikely(part_info->check_range_constants())) goto end; } else if (part_info->part_type == LIST_PARTITION) { error_str= partition_keywords[PKW_LIST].str; if (unlikely(part_info->check_list_constants())) goto end; } else { DBUG_ASSERT(0); my_error(ER_INCONSISTENT_PARTITION_INFO_ERROR, MYF(0)); goto end; } if (unlikely(part_info->no_parts < 1)) { my_error(ER_PARTITIONS_MUST_BE_DEFINED_ERROR, MYF(0), error_str); goto end; } if (unlikely(part_info->part_expr->result_type() != INT_RESULT)) { my_error(ER_PARTITION_FUNC_NOT_ALLOWED_ERROR, MYF(0), part_str); goto end; } } if (((part_info->part_type != HASH_PARTITION || part_info->list_of_part_fields == FALSE) && check_part_func_fields(part_info->part_field_array, TRUE)) || (part_info->list_of_part_fields == FALSE && part_info->is_sub_partitioned() && check_part_func_fields(part_info->subpart_field_array, TRUE))) { my_error(ER_PARTITION_FUNCTION_IS_NOT_ALLOWED, MYF(0)); goto end; } if (unlikely(create_full_part_field_array(thd, table, part_info))) goto end; if (unlikely(check_primary_key(table))) goto end; if (unlikely((!(table->s->db_type()->partition_flags && (table->s->db_type()->partition_flags() & HA_CAN_PARTITION_UNIQUE))) && check_unique_keys(table))) goto end; if (unlikely(set_up_partition_bitmap(thd, part_info))) goto end; if (unlikely(part_info->set_up_charset_field_preps())) { my_error(ER_PARTITION_FUNCTION_IS_NOT_ALLOWED, MYF(0)); goto end; } check_range_capable_PF(table); set_up_partition_key_maps(table, part_info); set_up_partition_func_pointers(part_info); set_up_range_analysis_info(part_info); result= FALSE; end: thd->mark_used_columns= save_mark_used_columns; DBUG_PRINT("info", ("thd->mark_used_columns: %d", thd->mark_used_columns)); DBUG_RETURN(result); } /* The code below is support routines for the reverse parsing of the partitioning syntax. This feature is very useful to generate syntax for all default values to avoid all default checking when opening the frm file. It is also used when altering the partitioning by use of various ALTER TABLE commands. Finally it is used for SHOW CREATE TABLES. */ static int add_write(File fptr, const char *buf, uint len) { uint len_written= my_write(fptr, (const uchar*)buf, len, MYF(0)); if (likely(len == len_written)) return 0; else return 1; } static int add_string_object(File fptr, String *string) { return add_write(fptr, string->ptr(), string->length()); } static int add_string(File fptr, const char *string) { return add_write(fptr, string, strlen(string)); } static int add_string_len(File fptr, const char *string, uint len) { return add_write(fptr, string, len); } static int add_space(File fptr) { return add_string(fptr, space_str); } static int add_comma(File fptr) { return add_string(fptr, comma_str); } static int add_equal(File fptr) { return add_string(fptr, equal_str); } static int add_end_parenthesis(File fptr) { return add_string(fptr, end_paren_str); } static int add_begin_parenthesis(File fptr) { return add_string(fptr, begin_paren_str); } static int add_part_key_word(File fptr, const char *key_string) { int err= add_string(fptr, key_string); err+= add_space(fptr); return err + add_begin_parenthesis(fptr); } static int add_hash(File fptr) { return add_part_key_word(fptr, partition_keywords[PKW_HASH].str); } static int add_partition(File fptr) { char buff[22]; strxmov(buff, part_str, space_str, NullS); return add_string(fptr, buff); } static int add_subpartition(File fptr) { int err= add_string(fptr, sub_str); return err + add_partition(fptr); } static int add_partition_by(File fptr) { char buff[22]; strxmov(buff, part_str, space_str, by_str, space_str, NullS); return add_string(fptr, buff); } static int add_subpartition_by(File fptr) { int err= add_string(fptr, sub_str); return err + add_partition_by(fptr); } static int add_key_partition(File fptr, List field_list) { uint i, no_fields; int err; List_iterator part_it(field_list); err= add_part_key_word(fptr, partition_keywords[PKW_KEY].str); no_fields= field_list.elements; i= 0; while (i < no_fields) { const char *field_str= part_it++; String field_string("", 0, system_charset_info); THD *thd= current_thd; ulonglong save_options= thd->options; thd->options= 0; append_identifier(thd, &field_string, field_str, strlen(field_str)); thd->options= save_options; err+= add_string_object(fptr, &field_string); if (i != (no_fields-1)) err+= add_comma(fptr); i++; } return err; } static int add_name_string(File fptr, const char *name) { int err; String name_string("", 0, system_charset_info); THD *thd= current_thd; ulonglong save_options= thd->options; thd->options= 0; append_identifier(thd, &name_string, name, strlen(name)); thd->options= save_options; err= add_string_object(fptr, &name_string); return err; } static int add_int(File fptr, longlong number) { char buff[32]; llstr(number, buff); return add_string(fptr, buff); } static int add_uint(File fptr, ulonglong number) { char buff[32]; longlong2str(number, buff, 10); return add_string(fptr, buff); } /* Must escape strings in partitioned tables frm-files, parsing it later with mysql_unpack_partition will fail otherwise. */ static int add_quoted_string(File fptr, const char *quotestr) { String orgstr(quotestr, system_charset_info); String escapedstr; int err= add_string(fptr, "'"); err+= append_escaped(&escapedstr, &orgstr); err+= add_string(fptr, escapedstr.c_ptr_safe()); return err + add_string(fptr, "'"); } static int add_keyword_string(File fptr, const char *keyword, bool should_use_quotes, const char *keystr) { int err= add_string(fptr, keyword); err+= add_space(fptr); err+= add_equal(fptr); err+= add_space(fptr); if (should_use_quotes) err+= add_quoted_string(fptr, keystr); else err+= add_string(fptr, keystr); return err + add_space(fptr); } static int add_keyword_int(File fptr, const char *keyword, longlong num) { int err= add_string(fptr, keyword); err+= add_space(fptr); err+= add_equal(fptr); err+= add_space(fptr); err+= add_int(fptr, num); return err + add_space(fptr); } static int add_engine(File fptr, handlerton *engine_type) { const char *engine_str= ha_resolve_storage_engine_name(engine_type); DBUG_PRINT("info", ("ENGINE: %s", engine_str)); int err= add_string(fptr, "ENGINE = "); return err + add_string(fptr, engine_str); } static int add_partition_options(File fptr, partition_element *p_elem) { int err= 0; err+= add_space(fptr); if (p_elem->tablespace_name) err+= add_keyword_string(fptr,"TABLESPACE", FALSE, p_elem->tablespace_name); if (p_elem->nodegroup_id != UNDEF_NODEGROUP) err+= add_keyword_int(fptr,"NODEGROUP",(longlong)p_elem->nodegroup_id); if (p_elem->part_max_rows) err+= add_keyword_int(fptr,"MAX_ROWS",(longlong)p_elem->part_max_rows); if (p_elem->part_min_rows) err+= add_keyword_int(fptr,"MIN_ROWS",(longlong)p_elem->part_min_rows); if (!(current_thd->variables.sql_mode & MODE_NO_DIR_IN_CREATE)) { if (p_elem->data_file_name) err+= add_keyword_string(fptr, "DATA DIRECTORY", TRUE, p_elem->data_file_name); if (p_elem->index_file_name) err+= add_keyword_string(fptr, "INDEX DIRECTORY", TRUE, p_elem->index_file_name); } if (p_elem->part_comment) err+= add_keyword_string(fptr, "COMMENT", TRUE, p_elem->part_comment); return err + add_engine(fptr,p_elem->engine_type); } static int add_partition_values(File fptr, partition_info *part_info, partition_element *p_elem) { int err= 0; if (part_info->part_type == RANGE_PARTITION) { err+= add_string(fptr, " VALUES LESS THAN "); if (!p_elem->max_value) { err+= add_begin_parenthesis(fptr); if (p_elem->signed_flag) err+= add_int(fptr, p_elem->range_value); else err+= add_uint(fptr, p_elem->range_value); err+= add_end_parenthesis(fptr); } else err+= add_string(fptr, partition_keywords[PKW_MAXVALUE].str); } else if (part_info->part_type == LIST_PARTITION) { uint i; List_iterator list_val_it(p_elem->list_val_list); err+= add_string(fptr, " VALUES IN "); uint no_items= p_elem->list_val_list.elements; err+= add_begin_parenthesis(fptr); if (p_elem->has_null_value) { err+= add_string(fptr, "NULL"); if (no_items == 0) { err+= add_end_parenthesis(fptr); goto end; } err+= add_comma(fptr); } i= 0; do { part_elem_value *list_value= list_val_it++; if (!list_value->unsigned_flag) err+= add_int(fptr, list_value->value); else err+= add_uint(fptr, list_value->value); if (i != (no_items-1)) err+= add_comma(fptr); } while (++i < no_items); err+= add_end_parenthesis(fptr); } end: return err; } /* Generate the partition syntax from the partition data structure. Useful for support of generating defaults, SHOW CREATE TABLES and easy partition management. SYNOPSIS generate_partition_syntax() part_info The partitioning data structure buf_length A pointer to the returned buffer length use_sql_alloc Allocate buffer from sql_alloc if true otherwise use my_malloc show_partition_options Should we display partition options RETURN VALUES NULL error buf, buf_length Buffer and its length DESCRIPTION Here we will generate the full syntax for the given command where all defaults have been expanded. By so doing the it is also possible to make lots of checks of correctness while at it. This could will also be reused for SHOW CREATE TABLES and also for all type ALTER TABLE commands focusing on changing the PARTITION structure in any fashion. The implementation writes the syntax to a temporary file (essentially an abstraction of a dynamic array) and if all writes goes well it allocates a buffer and writes the syntax into this one and returns it. As a security precaution the file is deleted before writing into it. This means that no other processes on the machine can open and read the file while this processing is ongoing. The code is optimised for minimal code size since it is not used in any common queries. */ char *generate_partition_syntax(partition_info *part_info, uint *buf_length, bool use_sql_alloc, bool show_partition_options) { uint i,j, tot_no_parts, no_subparts; partition_element *part_elem; ulonglong buffer_length; char path[FN_REFLEN]; int err= 0; List_iterator part_it(part_info->partitions); File fptr; char *buf= NULL; //Return buffer DBUG_ENTER("generate_partition_syntax"); if (unlikely(((fptr= create_temp_file(path,mysql_tmpdir,"psy", O_RDWR | O_BINARY | O_TRUNC | O_TEMPORARY, MYF(MY_WME)))) < 0)) DBUG_RETURN(NULL); #ifndef __WIN__ unlink(path); #endif err+= add_space(fptr); err+= add_partition_by(fptr); switch (part_info->part_type) { case RANGE_PARTITION: err+= add_part_key_word(fptr, partition_keywords[PKW_RANGE].str); break; case LIST_PARTITION: err+= add_part_key_word(fptr, partition_keywords[PKW_LIST].str); break; case HASH_PARTITION: if (part_info->linear_hash_ind) err+= add_string(fptr, partition_keywords[PKW_LINEAR].str); if (part_info->list_of_part_fields) err+= add_key_partition(fptr, part_info->part_field_list); else err+= add_hash(fptr); break; default: DBUG_ASSERT(0); /* We really shouldn't get here, no use in continuing from here */ my_error(ER_OUT_OF_RESOURCES, MYF(0)); current_thd->fatal_error(); DBUG_RETURN(NULL); } if (part_info->part_expr) err+= add_string_len(fptr, part_info->part_func_string, part_info->part_func_len); err+= add_end_parenthesis(fptr); if ((!part_info->use_default_no_partitions) && part_info->use_default_partitions) { err+= add_string(fptr, "\n"); err+= add_string(fptr, "PARTITIONS "); err+= add_int(fptr, part_info->no_parts); } if (part_info->is_sub_partitioned()) { err+= add_string(fptr, "\n"); err+= add_subpartition_by(fptr); /* Must be hash partitioning for subpartitioning */ if (part_info->linear_hash_ind) err+= add_string(fptr, partition_keywords[PKW_LINEAR].str); if (part_info->list_of_subpart_fields) err+= add_key_partition(fptr, part_info->subpart_field_list); else err+= add_hash(fptr); if (part_info->subpart_expr) err+= add_string_len(fptr, part_info->subpart_func_string, part_info->subpart_func_len); err+= add_end_parenthesis(fptr); if ((!part_info->use_default_no_subpartitions) && part_info->use_default_subpartitions) { err+= add_string(fptr, "\n"); err+= add_string(fptr, "SUBPARTITIONS "); err+= add_int(fptr, part_info->no_subparts); } } tot_no_parts= part_info->partitions.elements; no_subparts= part_info->no_subparts; if (!part_info->use_default_partitions) { bool first= TRUE; err+= add_string(fptr, "\n"); err+= add_begin_parenthesis(fptr); i= 0; do { part_elem= part_it++; if (part_elem->part_state != PART_TO_BE_DROPPED && part_elem->part_state != PART_REORGED_DROPPED) { if (!first) { err+= add_comma(fptr); err+= add_string(fptr, "\n"); err+= add_space(fptr); } first= FALSE; err+= add_partition(fptr); err+= add_name_string(fptr, part_elem->partition_name); err+= add_partition_values(fptr, part_info, part_elem); if (!part_info->is_sub_partitioned() || part_info->use_default_subpartitions) { if (show_partition_options) err+= add_partition_options(fptr, part_elem); } else { err+= add_string(fptr, "\n"); err+= add_space(fptr); err+= add_begin_parenthesis(fptr); List_iterator sub_it(part_elem->subpartitions); j= 0; do { part_elem= sub_it++; err+= add_subpartition(fptr); err+= add_name_string(fptr, part_elem->partition_name); if (show_partition_options) err+= add_partition_options(fptr, part_elem); if (j != (no_subparts-1)) { err+= add_comma(fptr); err+= add_string(fptr, "\n"); err+= add_space(fptr); err+= add_space(fptr); } else err+= add_end_parenthesis(fptr); } while (++j < no_subparts); } } if (i == (tot_no_parts-1)) err+= add_end_parenthesis(fptr); } while (++i < tot_no_parts); } if (err) goto close_file; buffer_length= my_seek(fptr, 0L,MY_SEEK_END,MYF(0)); if (unlikely(buffer_length == MY_FILEPOS_ERROR)) goto close_file; if (unlikely(my_seek(fptr, 0L, MY_SEEK_SET, MYF(0)) == MY_FILEPOS_ERROR)) goto close_file; *buf_length= (uint)buffer_length; if (use_sql_alloc) buf= (char*) sql_alloc(*buf_length+1); else buf= (char*) my_malloc(*buf_length+1, MYF(MY_WME)); if (!buf) goto close_file; if (unlikely(my_read(fptr, (uchar*)buf, *buf_length, MYF(MY_FNABP)))) { if (!use_sql_alloc) my_free(buf, MYF(0)); else buf= NULL; } else buf[*buf_length]= 0; close_file: my_close(fptr, MYF(0)); DBUG_RETURN(buf); } /* Check if partition key fields are modified and if it can be handled by the underlying storage engine. SYNOPSIS partition_key_modified table TABLE object for which partition fields are set-up fields Bitmap representing fields to be modified RETURN VALUES TRUE Need special handling of UPDATE FALSE Normal UPDATE handling is ok */ bool partition_key_modified(TABLE *table, const MY_BITMAP *fields) { Field **fld; partition_info *part_info= table->part_info; DBUG_ENTER("partition_key_modified"); if (!part_info) DBUG_RETURN(FALSE); if (table->s->db_type()->partition_flags && (table->s->db_type()->partition_flags() & HA_CAN_UPDATE_PARTITION_KEY)) DBUG_RETURN(FALSE); for (fld= part_info->full_part_field_array; *fld; fld++) if (bitmap_is_set(fields, (*fld)->field_index)) DBUG_RETURN(TRUE); DBUG_RETURN(FALSE); } /* A function to handle correct handling of NULL values in partition functions. SYNOPSIS part_val_int() item_expr The item expression to evaluate out:result The value of the partition function, LONGLONG_MIN if any null value in function RETURN VALUES TRUE Error in val_int() FALSE ok */ static inline int part_val_int(Item *item_expr, longlong *result) { *result= item_expr->val_int(); if (item_expr->null_value) { if (current_thd->is_error()) return TRUE; else *result= LONGLONG_MIN; } return FALSE; } /* The next set of functions are used to calculate the partition identity. A handler sets up a variable that corresponds to one of these functions to be able to quickly call it whenever the partition id needs to calculated based on the record in table->record[0] (or set up to fake that). There are 4 functions for hash partitioning and 2 for RANGE/LIST partitions. In addition there are 4 variants for RANGE subpartitioning and 4 variants for LIST subpartitioning thus in total there are 14 variants of this function. We have a set of support functions for these 14 variants. There are 4 variants of hash functions and there is a function for each. The KEY partitioning uses the function calculate_key_value to calculate the hash value based on an array of fields. The linear hash variants uses the method get_part_id_from_linear_hash to get the partition id using the hash value and some parameters calculated from the number of partitions. */ /* Calculate hash value for KEY partitioning using an array of fields. SYNOPSIS calculate_key_value() field_array An array of the fields in KEY partitioning RETURN VALUE hash_value calculated DESCRIPTION Uses the hash function on the character set of the field. Integer and floating point fields use the binary character set by default. */ static uint32 calculate_key_value(Field **field_array) { ulong nr1= 1; ulong nr2= 4; do { Field *field= *field_array; field->hash(&nr1, &nr2); } while (*(++field_array)); return (uint32) nr1; } /* A simple support function to calculate part_id given local part and sub part. SYNOPSIS get_part_id_for_sub() loc_part_id Local partition id sub_part_id Subpartition id no_subparts Number of subparts */ inline static uint32 get_part_id_for_sub(uint32 loc_part_id, uint32 sub_part_id, uint no_subparts) { return (uint32)((loc_part_id * no_subparts) + sub_part_id); } /* Calculate part_id for (SUB)PARTITION BY HASH SYNOPSIS get_part_id_hash() no_parts Number of hash partitions part_expr Item tree of hash function out:part_id The returned partition id out:func_value Value of hash function RETURN VALUE != 0 Error code FALSE Success */ static int get_part_id_hash(uint no_parts, Item *part_expr, uint32 *part_id, longlong *func_value) { longlong int_hash_id; DBUG_ENTER("get_part_id_hash"); if (part_val_int(part_expr, func_value)) DBUG_RETURN(HA_ERR_NO_PARTITION_FOUND); int_hash_id= *func_value % no_parts; *part_id= int_hash_id < 0 ? (uint32) -int_hash_id : (uint32) int_hash_id; DBUG_RETURN(FALSE); } /* Calculate part_id for (SUB)PARTITION BY LINEAR HASH SYNOPSIS get_part_id_linear_hash() part_info A reference to the partition_info struct where all the desired information is given no_parts Number of hash partitions part_expr Item tree of hash function out:part_id The returned partition id out:func_value Value of hash function RETURN VALUE != 0 Error code 0 OK */ static int get_part_id_linear_hash(partition_info *part_info, uint no_parts, Item *part_expr, uint32 *part_id, longlong *func_value) { DBUG_ENTER("get_part_id_linear_hash"); if (part_val_int(part_expr, func_value)) DBUG_RETURN(HA_ERR_NO_PARTITION_FOUND); *part_id= get_part_id_from_linear_hash(*func_value, part_info->linear_hash_mask, no_parts); DBUG_RETURN(FALSE); } /* Calculate part_id for (SUB)PARTITION BY KEY SYNOPSIS get_part_id_key() field_array Array of fields for PARTTION KEY no_parts Number of KEY partitions RETURN VALUE Calculated partition id */ inline static uint32 get_part_id_key(Field **field_array, uint no_parts, longlong *func_value) { DBUG_ENTER("get_part_id_key"); *func_value= calculate_key_value(field_array); DBUG_RETURN((uint32) (*func_value % no_parts)); } /* Calculate part_id for (SUB)PARTITION BY LINEAR KEY SYNOPSIS get_part_id_linear_key() part_info A reference to the partition_info struct where all the desired information is given field_array Array of fields for PARTTION KEY no_parts Number of KEY partitions RETURN VALUE Calculated partition id */ inline static uint32 get_part_id_linear_key(partition_info *part_info, Field **field_array, uint no_parts, longlong *func_value) { DBUG_ENTER("get_partition_id_linear_key"); *func_value= calculate_key_value(field_array); DBUG_RETURN(get_part_id_from_linear_hash(*func_value, part_info->linear_hash_mask, no_parts)); } /* Copy to field buffers and set up field pointers SYNOPSIS copy_to_part_field_buffers() ptr Array of fields to copy field_bufs Array of field buffers to copy to restore_ptr Array of pointers to restore to RETURN VALUES NONE DESCRIPTION This routine is used to take the data from field pointer, convert it to a standard format and store this format in a field buffer allocated for this purpose. Next the field pointers are moved to point to the field buffers. There is a separate to restore the field pointers after this call. */ static void copy_to_part_field_buffers(Field **ptr, uchar **field_bufs, uchar **restore_ptr) { Field *field; while ((field= *(ptr++))) { *restore_ptr= field->ptr; restore_ptr++; if (!field->maybe_null() || !field->is_null()) { CHARSET_INFO *cs= ((Field_str*)field)->charset(); uint len= field->pack_length(); uchar *field_buf= *field_bufs; /* We only use the field buffer for VARCHAR and CHAR strings which isn't of a binary collation. We also only use the field buffer for fields which are not currently NULL. The field buffer will store a normalised string. We use the strnxfrm method to normalise the string. */ if (field->type() == MYSQL_TYPE_VARCHAR) { uint len_bytes= ((Field_varstring*)field)->length_bytes; my_strnxfrm(cs, field_buf + len_bytes, (len - len_bytes), field->ptr + len_bytes, field->field_length); if (len_bytes == 1) *field_buf= (uchar) field->field_length; else int2store(field_buf, field->field_length); } else { my_strnxfrm(cs, field_buf, len, field->ptr, field->field_length); } field->ptr= field_buf; } field_bufs++; } return; } /* Restore field pointers SYNOPSIS restore_part_field_pointers() ptr Array of fields to restore restore_ptr Array of field pointers to restore to RETURN VALUES */ static void restore_part_field_pointers(Field **ptr, uchar **restore_ptr) { Field *field; while ((field= *(ptr++))) { field->ptr= *restore_ptr; restore_ptr++; } return; } /* This function is used to calculate the main partition to use in the case of subpartitioning and we don't know enough to get the partition identity in total. SYNOPSIS get_part_partition_id() part_info A reference to the partition_info struct where all the desired information is given out:part_id The partition id is returned through this pointer out:func_value The value calculated by partition function RETURN VALUE HA_ERR_NO_PARTITION_FOUND The fields of the partition function didn't fit into any partition and thus the values of the PF-fields are not allowed. 0 OK DESCRIPTION It is actually 6 different variants of this function which are called through a function pointer. get_partition_id_list get_partition_id_range get_partition_id_hash_nosub get_partition_id_key_nosub get_partition_id_linear_hash_nosub get_partition_id_linear_key_nosub */ static int get_part_id_charset_func_subpart(partition_info *part_info, uint32 *part_id, longlong *func_value) { int res; copy_to_part_field_buffers(part_info->subpart_charset_field_array, part_info->subpart_field_buffers, part_info->restore_subpart_field_ptrs); res= part_info->get_partition_id_charset(part_info, part_id, func_value); restore_part_field_pointers(part_info->subpart_charset_field_array, part_info->restore_subpart_field_ptrs); return res; } static int get_part_id_charset_func_part(partition_info *part_info, uint32 *part_id, longlong *func_value) { int res; copy_to_part_field_buffers(part_info->part_charset_field_array, part_info->part_field_buffers, part_info->restore_part_field_ptrs); res= part_info->get_partition_id_charset(part_info, part_id, func_value); restore_part_field_pointers(part_info->part_charset_field_array, part_info->restore_part_field_ptrs); return res; } static int get_part_id_charset_func_all(partition_info *part_info, uint32 *part_id, longlong *func_value) { int res; copy_to_part_field_buffers(part_info->full_part_field_array, part_info->full_part_field_buffers, part_info->restore_full_part_field_ptrs); res= part_info->get_partition_id_charset(part_info, part_id, func_value); restore_part_field_pointers(part_info->full_part_field_array, part_info->restore_full_part_field_ptrs); return res; } static int get_part_part_id_charset_func(partition_info *part_info, uint32 *part_id, longlong *func_value) { int res; copy_to_part_field_buffers(part_info->part_charset_field_array, part_info->part_field_buffers, part_info->restore_part_field_ptrs); res= part_info->get_part_partition_id_charset(part_info, part_id, func_value); restore_part_field_pointers(part_info->part_charset_field_array, part_info->restore_part_field_ptrs); return res; } static int get_subpart_id_charset_func(partition_info *part_info, uint32 *part_id) { int res; copy_to_part_field_buffers(part_info->subpart_charset_field_array, part_info->subpart_field_buffers, part_info->restore_subpart_field_ptrs); res= part_info->get_subpartition_id_charset(part_info, part_id); restore_part_field_pointers(part_info->subpart_charset_field_array, part_info->restore_subpart_field_ptrs); return res; } int get_partition_id_list(partition_info *part_info, uint32 *part_id, longlong *func_value) { LIST_PART_ENTRY *list_array= part_info->list_array; int list_index; int min_list_index= 0; int max_list_index= part_info->no_list_values - 1; longlong part_func_value; int error= part_val_int(part_info->part_expr, &part_func_value); longlong list_value; bool unsigned_flag= part_info->part_expr->unsigned_flag; DBUG_ENTER("get_partition_id_list"); if (error) goto notfound; if (part_info->part_expr->null_value) { if (part_info->has_null_value) { *part_id= part_info->has_null_part_id; DBUG_RETURN(0); } goto notfound; } *func_value= part_func_value; if (unsigned_flag) part_func_value-= 0x8000000000000000ULL; while (max_list_index >= min_list_index) { list_index= (max_list_index + min_list_index) >> 1; list_value= list_array[list_index].list_value; if (list_value < part_func_value) min_list_index= list_index + 1; else if (list_value > part_func_value) { if (!list_index) goto notfound; max_list_index= list_index - 1; } else { *part_id= (uint32)list_array[list_index].partition_id; DBUG_RETURN(0); } } notfound: *part_id= 0; DBUG_RETURN(HA_ERR_NO_PARTITION_FOUND); } /* Find the sub-array part_info->list_array that corresponds to given interval SYNOPSIS get_list_array_idx_for_endpoint() part_info Partitioning info (partitioning type must be LIST) left_endpoint TRUE - the interval is [a; +inf) or (a; +inf) FALSE - the interval is (-inf; a] or (-inf; a) include_endpoint TRUE iff the interval includes the endpoint DESCRIPTION This function finds the sub-array of part_info->list_array where values of list_array[idx].list_value are contained within the specifed interval. list_array is ordered by list_value, so 1. For [a; +inf) or (a; +inf)-type intervals (left_endpoint==TRUE), the sought sub-array starts at some index idx and continues till array end. The function returns first number idx, such that list_array[idx].list_value is contained within the passed interval. 2. For (-inf; a] or (-inf; a)-type intervals (left_endpoint==FALSE), the sought sub-array starts at array start and continues till some last index idx. The function returns first number idx, such that list_array[idx].list_value is NOT contained within the passed interval. If all array elements are contained, part_info->no_list_values is returned. NOTE The caller will call this function and then will run along the sub-array of list_array to collect partition ids. If the number of list values is significantly higher then number of partitions, this could be slow and we could invent some other approach. The "run over list array" part is already wrapped in a get_next()-like function. RETURN The edge of corresponding sub-array of part_info->list_array */ uint32 get_list_array_idx_for_endpoint_charset(partition_info *part_info, bool left_endpoint, bool include_endpoint) { uint32 res; copy_to_part_field_buffers(part_info->part_field_array, part_info->part_field_buffers, part_info->restore_part_field_ptrs); res= get_list_array_idx_for_endpoint(part_info, left_endpoint, include_endpoint); restore_part_field_pointers(part_info->part_field_array, part_info->restore_part_field_ptrs); return res; } uint32 get_list_array_idx_for_endpoint(partition_info *part_info, bool left_endpoint, bool include_endpoint) { LIST_PART_ENTRY *list_array= part_info->list_array; uint list_index; uint min_list_index= 0, max_list_index= part_info->no_list_values - 1; longlong list_value; /* Get the partitioning function value for the endpoint */ longlong part_func_value= part_info->part_expr->val_int_endpoint(left_endpoint, &include_endpoint); bool unsigned_flag= part_info->part_expr->unsigned_flag; DBUG_ENTER("get_list_array_idx_for_endpoint"); if (part_info->part_expr->null_value) { DBUG_RETURN(0); } if (unsigned_flag) part_func_value-= 0x8000000000000000ULL; DBUG_ASSERT(part_info->no_list_values); do { list_index= (max_list_index + min_list_index) >> 1; list_value= list_array[list_index].list_value; if (list_value < part_func_value) min_list_index= list_index + 1; else if (list_value > part_func_value) { if (!list_index) goto notfound; max_list_index= list_index - 1; } else { DBUG_RETURN(list_index + test(left_endpoint ^ include_endpoint)); } } while (max_list_index >= min_list_index); notfound: if (list_value < part_func_value) list_index++; DBUG_RETURN(list_index); } int get_partition_id_range(partition_info *part_info, uint32 *part_id, longlong *func_value) { longlong *range_array= part_info->range_int_array; uint max_partition= part_info->no_parts - 1; uint min_part_id= 0; uint max_part_id= max_partition; uint loc_part_id; longlong part_func_value; int error= part_val_int(part_info->part_expr, &part_func_value); bool unsigned_flag= part_info->part_expr->unsigned_flag; DBUG_ENTER("get_partition_id_range"); if (error) DBUG_RETURN(HA_ERR_NO_PARTITION_FOUND); if (part_info->part_expr->null_value) { *part_id= 0; DBUG_RETURN(0); } *func_value= part_func_value; if (unsigned_flag) part_func_value-= 0x8000000000000000ULL; while (max_part_id > min_part_id) { loc_part_id= (max_part_id + min_part_id + 1) >> 1; if (range_array[loc_part_id] <= part_func_value) min_part_id= loc_part_id + 1; else max_part_id= loc_part_id - 1; } loc_part_id= max_part_id; if (part_func_value >= range_array[loc_part_id]) if (loc_part_id != max_partition) loc_part_id++; *part_id= (uint32)loc_part_id; if (loc_part_id == max_partition && part_func_value >= range_array[loc_part_id] && !part_info->defined_max_value) DBUG_RETURN(HA_ERR_NO_PARTITION_FOUND); DBUG_PRINT("exit",("partition: %d", *part_id)); DBUG_RETURN(0); } /* Find the sub-array of part_info->range_int_array that covers given interval SYNOPSIS get_partition_id_range_for_endpoint() part_info Partitioning info (partitioning type must be RANGE) left_endpoint TRUE - the interval is [a; +inf) or (a; +inf) FALSE - the interval is (-inf; a] or (-inf; a). include_endpoint TRUE <=> the endpoint itself is included in the interval DESCRIPTION This function finds the sub-array of part_info->range_int_array where the elements have non-empty intersections with the given interval. A range_int_array element at index idx represents the interval [range_int_array[idx-1], range_int_array[idx]), intervals are disjoint and ordered by their right bound, so 1. For [a; +inf) or (a; +inf)-type intervals (left_endpoint==TRUE), the sought sub-array starts at some index idx and continues till array end. The function returns first number idx, such that the interval represented by range_int_array[idx] has non empty intersection with the passed interval. 2. For (-inf; a] or (-inf; a)-type intervals (left_endpoint==FALSE), the sought sub-array starts at array start and continues till some last index idx. The function returns first number idx, such that the interval represented by range_int_array[idx] has EMPTY intersection with the passed interval. If the interval represented by the last array element has non-empty intersection with the passed interval, part_info->no_parts is returned. RETURN The edge of corresponding part_info->range_int_array sub-array. */ static uint32 get_partition_id_range_for_endpoint_charset(partition_info *part_info, bool left_endpoint, bool include_endpoint) { uint32 res; copy_to_part_field_buffers(part_info->part_field_array, part_info->part_field_buffers, part_info->restore_part_field_ptrs); res= get_partition_id_range_for_endpoint(part_info, left_endpoint, include_endpoint); restore_part_field_pointers(part_info->part_field_array, part_info->restore_part_field_ptrs); return res; } uint32 get_partition_id_range_for_endpoint(partition_info *part_info, bool left_endpoint, bool include_endpoint) { longlong *range_array= part_info->range_int_array; uint max_partition= part_info->no_parts - 1; uint min_part_id= 0, max_part_id= max_partition, loc_part_id; /* Get the partitioning function value for the endpoint */ longlong part_func_value= part_info->part_expr->val_int_endpoint(left_endpoint, &include_endpoint); bool unsigned_flag= part_info->part_expr->unsigned_flag; DBUG_ENTER("get_partition_id_range_for_endpoint"); if (part_info->part_expr->null_value) { uint32 ret_part_id= 0; if (!left_endpoint && include_endpoint) ret_part_id= 1; DBUG_RETURN(ret_part_id); } if (unsigned_flag) part_func_value-= 0x8000000000000000ULL; if (left_endpoint && !include_endpoint) part_func_value++; while (max_part_id > min_part_id) { loc_part_id= (max_part_id + min_part_id + 1) >> 1; if (range_array[loc_part_id] <= part_func_value) min_part_id= loc_part_id + 1; else max_part_id= loc_part_id - 1; } loc_part_id= max_part_id; if (loc_part_id < max_partition && part_func_value >= range_array[loc_part_id+1]) { loc_part_id++; } if (left_endpoint) { longlong bound= range_array[loc_part_id]; /* In case of PARTITION p VALUES LESS THAN MAXVALUE the maximum value is in the current partition. */ if (part_func_value > bound || (part_func_value == bound && !part_info->defined_max_value)) loc_part_id++; } else { if (loc_part_id < max_partition) { if (part_func_value == range_array[loc_part_id]) loc_part_id += test(include_endpoint); else if (part_func_value > range_array[loc_part_id]) loc_part_id++; } loc_part_id++; } DBUG_RETURN(loc_part_id); } int get_partition_id_hash_nosub(partition_info *part_info, uint32 *part_id, longlong *func_value) { return get_part_id_hash(part_info->no_parts, part_info->part_expr, part_id, func_value); } int get_partition_id_linear_hash_nosub(partition_info *part_info, uint32 *part_id, longlong *func_value) { return get_part_id_linear_hash(part_info, part_info->no_parts, part_info->part_expr, part_id, func_value); } int get_partition_id_key_nosub(partition_info *part_info, uint32 *part_id, longlong *func_value) { *part_id= get_part_id_key(part_info->part_field_array, part_info->no_parts, func_value); return 0; } int get_partition_id_linear_key_nosub(partition_info *part_info, uint32 *part_id, longlong *func_value) { *part_id= get_part_id_linear_key(part_info, part_info->part_field_array, part_info->no_parts, func_value); return 0; } int get_partition_id_range_sub_hash(partition_info *part_info, uint32 *part_id, longlong *func_value) { uint32 loc_part_id, sub_part_id; uint no_subparts; longlong local_func_value; int error; DBUG_ENTER("get_partition_id_range_sub_hash"); LINT_INIT(loc_part_id); LINT_INIT(sub_part_id); if (unlikely((error= get_partition_id_range(part_info, &loc_part_id, func_value)))) { DBUG_RETURN(error); } no_subparts= part_info->no_subparts; if (unlikely((error= get_part_id_hash(no_subparts, part_info->subpart_expr, &sub_part_id, &local_func_value)))) { DBUG_RETURN(error); } *part_id= get_part_id_for_sub(loc_part_id, sub_part_id, no_subparts); DBUG_RETURN(0); } int get_partition_id_range_sub_linear_hash(partition_info *part_info, uint32 *part_id, longlong *func_value) { uint32 loc_part_id, sub_part_id; uint no_subparts; longlong local_func_value; int error; DBUG_ENTER("get_partition_id_range_sub_linear_hash"); LINT_INIT(loc_part_id); LINT_INIT(sub_part_id); if (unlikely((error= get_partition_id_range(part_info, &loc_part_id, func_value)))) { DBUG_RETURN(error); } no_subparts= part_info->no_subparts; if (unlikely((error= get_part_id_linear_hash(part_info, no_subparts, part_info->subpart_expr, &sub_part_id, &local_func_value)))) { DBUG_RETURN(error); } *part_id= get_part_id_for_sub(loc_part_id, sub_part_id, no_subparts); DBUG_RETURN(0); } int get_partition_id_range_sub_key(partition_info *part_info, uint32 *part_id, longlong *func_value) { uint32 loc_part_id, sub_part_id; uint no_subparts; longlong local_func_value; int error; DBUG_ENTER("get_partition_id_range_sub_key"); LINT_INIT(loc_part_id); if (unlikely((error= get_partition_id_range(part_info, &loc_part_id, func_value)))) { DBUG_RETURN(error); } no_subparts= part_info->no_subparts; sub_part_id= get_part_id_key(part_info->subpart_field_array, no_subparts, &local_func_value); *part_id= get_part_id_for_sub(loc_part_id, sub_part_id, no_subparts); DBUG_RETURN(0); } int get_partition_id_range_sub_linear_key(partition_info *part_info, uint32 *part_id, longlong *func_value) { uint32 loc_part_id, sub_part_id; uint no_subparts; longlong local_func_value; int error; DBUG_ENTER("get_partition_id_range_sub_linear_key"); LINT_INIT(loc_part_id); if (unlikely((error= get_partition_id_range(part_info, &loc_part_id, func_value)))) { DBUG_RETURN(error); } no_subparts= part_info->no_subparts; sub_part_id= get_part_id_linear_key(part_info, part_info->subpart_field_array, no_subparts, &local_func_value); *part_id= get_part_id_for_sub(loc_part_id, sub_part_id, no_subparts); DBUG_RETURN(0); } int get_partition_id_list_sub_hash(partition_info *part_info, uint32 *part_id, longlong *func_value) { uint32 loc_part_id, sub_part_id; uint no_subparts; longlong local_func_value; int error; DBUG_ENTER("get_partition_id_list_sub_hash"); LINT_INIT(sub_part_id); if (unlikely((error= get_partition_id_list(part_info, &loc_part_id, func_value)))) { DBUG_RETURN(error); } no_subparts= part_info->no_subparts; if (unlikely((error= get_part_id_hash(no_subparts, part_info->subpart_expr, &sub_part_id, &local_func_value)))) { DBUG_RETURN(error); } *part_id= get_part_id_for_sub(loc_part_id, sub_part_id, no_subparts); DBUG_RETURN(0); } int get_partition_id_list_sub_linear_hash(partition_info *part_info, uint32 *part_id, longlong *func_value) { uint32 loc_part_id, sub_part_id; uint no_subparts; longlong local_func_value; int error; DBUG_ENTER("get_partition_id_list_sub_linear_hash"); LINT_INIT(sub_part_id); if (unlikely((error= get_partition_id_list(part_info, &loc_part_id, func_value)))) { DBUG_RETURN(error); } no_subparts= part_info->no_subparts; if (unlikely((error= get_part_id_linear_hash(part_info, no_subparts, part_info->subpart_expr, &sub_part_id, &local_func_value)))) { DBUG_RETURN(error); } *part_id= get_part_id_for_sub(loc_part_id, sub_part_id, no_subparts); DBUG_RETURN(0); } int get_partition_id_list_sub_key(partition_info *part_info, uint32 *part_id, longlong *func_value) { uint32 loc_part_id, sub_part_id; uint no_subparts; longlong local_func_value; int error; DBUG_ENTER("get_partition_id_range_sub_key"); if (unlikely((error= get_partition_id_list(part_info, &loc_part_id, func_value)))) { DBUG_RETURN(error); } no_subparts= part_info->no_subparts; sub_part_id= get_part_id_key(part_info->subpart_field_array, no_subparts, &local_func_value); *part_id= get_part_id_for_sub(loc_part_id, sub_part_id, no_subparts); DBUG_RETURN(0); } int get_partition_id_list_sub_linear_key(partition_info *part_info, uint32 *part_id, longlong *func_value) { uint32 loc_part_id, sub_part_id; uint no_subparts; longlong local_func_value; int error; DBUG_ENTER("get_partition_id_list_sub_linear_key"); if (unlikely((error= get_partition_id_list(part_info, &loc_part_id, func_value)))) { DBUG_RETURN(error); } no_subparts= part_info->no_subparts; sub_part_id= get_part_id_linear_key(part_info, part_info->subpart_field_array, no_subparts, &local_func_value); *part_id= get_part_id_for_sub(loc_part_id, sub_part_id, no_subparts); DBUG_RETURN(0); } /* This function is used to calculate the subpartition id SYNOPSIS get_subpartition_id() part_info A reference to the partition_info struct where all the desired information is given RETURN VALUE part_id The subpartition identity DESCRIPTION A routine used in some SELECT's when only partial knowledge of the partitions is known. It is actually 4 different variants of this function which are called through a function pointer. get_partition_id_hash_sub get_partition_id_key_sub get_partition_id_linear_hash_sub get_partition_id_linear_key_sub */ int get_partition_id_hash_sub(partition_info *part_info, uint32 *part_id) { longlong func_value; return get_part_id_hash(part_info->no_subparts, part_info->subpart_expr, part_id, &func_value); } int get_partition_id_linear_hash_sub(partition_info *part_info, uint32 *part_id) { longlong func_value; return get_part_id_linear_hash(part_info, part_info->no_subparts, part_info->subpart_expr, part_id, &func_value); } int get_partition_id_key_sub(partition_info *part_info, uint32 *part_id) { longlong func_value; *part_id= get_part_id_key(part_info->subpart_field_array, part_info->no_subparts, &func_value); return FALSE; } int get_partition_id_linear_key_sub(partition_info *part_info, uint32 *part_id) { longlong func_value; *part_id= get_part_id_linear_key(part_info, part_info->subpart_field_array, part_info->no_subparts, &func_value); return FALSE; } /* Set an indicator on all partition fields that are set by the key SYNOPSIS set_PF_fields_in_key() key_info Information about the index key_length Length of key RETURN VALUE TRUE Found partition field set by key FALSE No partition field set by key */ static bool set_PF_fields_in_key(KEY *key_info, uint key_length) { KEY_PART_INFO *key_part; bool found_part_field= FALSE; DBUG_ENTER("set_PF_fields_in_key"); for (key_part= key_info->key_part; (int)key_length > 0; key_part++) { if (key_part->null_bit) key_length--; if (key_part->type == HA_KEYTYPE_BIT) { if (((Field_bit*)key_part->field)->bit_len) key_length--; } if (key_part->key_part_flag & (HA_BLOB_PART + HA_VAR_LENGTH_PART)) { key_length-= HA_KEY_BLOB_LENGTH; } if (key_length < key_part->length) break; key_length-= key_part->length; if (key_part->field->flags & FIELD_IN_PART_FUNC_FLAG) { found_part_field= TRUE; key_part->field->flags|= GET_FIXED_FIELDS_FLAG; } } DBUG_RETURN(found_part_field); } /* We have found that at least one partition field was set by a key, now check if a partition function has all its fields bound or not. SYNOPSIS check_part_func_bound() ptr Array of fields NULL terminated (partition fields) RETURN VALUE TRUE All fields in partition function are set FALSE Not all fields in partition function are set */ static bool check_part_func_bound(Field **ptr) { bool result= TRUE; DBUG_ENTER("check_part_func_bound"); for (; *ptr; ptr++) { if (!((*ptr)->flags & GET_FIXED_FIELDS_FLAG)) { result= FALSE; break; } } DBUG_RETURN(result); } /* Get the id of the subpartitioning part by using the key buffer of the index scan. SYNOPSIS get_sub_part_id_from_key() table The table object buf A buffer that can be used to evaluate the partition function key_info The index object key_spec A key_range containing key and key length out:part_id The returned partition id RETURN VALUES TRUE All fields in partition function are set FALSE Not all fields in partition function are set DESCRIPTION Use key buffer to set-up record in buf, move field pointers and get the partition identity and restore field pointers afterwards. */ static int get_sub_part_id_from_key(const TABLE *table,uchar *buf, KEY *key_info, const key_range *key_spec, uint32 *part_id) { uchar *rec0= table->record[0]; partition_info *part_info= table->part_info; int res; DBUG_ENTER("get_sub_part_id_from_key"); key_restore(buf, (uchar*)key_spec->key, key_info, key_spec->length); if (likely(rec0 == buf)) { res= part_info->get_subpartition_id(part_info, part_id); } else { Field **part_field_array= part_info->subpart_field_array; set_field_ptr(part_field_array, buf, rec0); res= part_info->get_subpartition_id(part_info, part_id); set_field_ptr(part_field_array, rec0, buf); } DBUG_RETURN(res); } /* Get the id of the partitioning part by using the key buffer of the index scan. SYNOPSIS get_part_id_from_key() table The table object buf A buffer that can be used to evaluate the partition function key_info The index object key_spec A key_range containing key and key length out:part_id Partition to use RETURN VALUES TRUE Partition to use not found FALSE Ok, part_id indicates partition to use DESCRIPTION Use key buffer to set-up record in buf, move field pointers and get the partition identity and restore field pointers afterwards. */ bool get_part_id_from_key(const TABLE *table, uchar *buf, KEY *key_info, const key_range *key_spec, uint32 *part_id) { bool result; uchar *rec0= table->record[0]; partition_info *part_info= table->part_info; longlong func_value; DBUG_ENTER("get_part_id_from_key"); key_restore(buf, (uchar*)key_spec->key, key_info, key_spec->length); if (likely(rec0 == buf)) { result= part_info->get_part_partition_id(part_info, part_id, &func_value); } else { Field **part_field_array= part_info->part_field_array; set_field_ptr(part_field_array, buf, rec0); result= part_info->get_part_partition_id(part_info, part_id, &func_value); set_field_ptr(part_field_array, rec0, buf); } DBUG_RETURN(result); } /* Get the partitioning id of the full PF by using the key buffer of the index scan. SYNOPSIS get_full_part_id_from_key() table The table object buf A buffer that is used to evaluate the partition function key_info The index object key_spec A key_range containing key and key length out:part_spec A partition id containing start part and end part RETURN VALUES part_spec No partitions to scan is indicated by end_part > start_part when returning DESCRIPTION Use key buffer to set-up record in buf, move field pointers if needed and get the partition identity and restore field pointers afterwards. */ void get_full_part_id_from_key(const TABLE *table, uchar *buf, KEY *key_info, const key_range *key_spec, part_id_range *part_spec) { bool result; partition_info *part_info= table->part_info; uchar *rec0= table->record[0]; longlong func_value; DBUG_ENTER("get_full_part_id_from_key"); key_restore(buf, (uchar*)key_spec->key, key_info, key_spec->length); if (likely(rec0 == buf)) { result= part_info->get_partition_id(part_info, &part_spec->start_part, &func_value); } else { Field **part_field_array= part_info->full_part_field_array; set_field_ptr(part_field_array, buf, rec0); result= part_info->get_partition_id(part_info, &part_spec->start_part, &func_value); set_field_ptr(part_field_array, rec0, buf); } part_spec->end_part= part_spec->start_part; if (unlikely(result)) part_spec->start_part++; DBUG_VOID_RETURN; } /* Prune the set of partitions to use in query SYNOPSIS prune_partition_set() table The table object out:part_spec Contains start part, end part DESCRIPTION This function is called to prune the range of partitions to scan by checking the used_partitions bitmap. If start_part > end_part at return it means no partition needs to be scanned. If start_part == end_part it always means a single partition needs to be scanned. RETURN VALUE part_spec */ void prune_partition_set(const TABLE *table, part_id_range *part_spec) { int last_partition= -1; uint i; partition_info *part_info= table->part_info; DBUG_ENTER("prune_partition_set"); for (i= part_spec->start_part; i <= part_spec->end_part; i++) { if (bitmap_is_set(&(part_info->used_partitions), i)) { DBUG_PRINT("info", ("Partition %d is set", i)); if (last_partition == -1) /* First partition found in set and pruned bitmap */ part_spec->start_part= i; last_partition= i; } } if (last_partition == -1) /* No partition found in pruned bitmap */ part_spec->start_part= part_spec->end_part + 1; else //if (last_partition != -1) part_spec->end_part= last_partition; DBUG_VOID_RETURN; } /* Get the set of partitions to use in query. SYNOPSIS get_partition_set() table The table object buf A buffer that can be used to evaluate the partition function index The index of the key used, if MAX_KEY no index used key_spec A key_range containing key and key length out:part_spec Contains start part, end part and indicator if bitmap is used for which partitions to scan DESCRIPTION This function is called to discover which partitions to use in an index scan or a full table scan. It returns a range of partitions to scan. If there are holes in this range with partitions that are not needed to scan a bit array is used to signal which partitions to use and which not to use. If start_part > end_part at return it means no partition needs to be scanned. If start_part == end_part it always means a single partition needs to be scanned. RETURN VALUE part_spec */ void get_partition_set(const TABLE *table, uchar *buf, const uint index, const key_range *key_spec, part_id_range *part_spec) { partition_info *part_info= table->part_info; uint no_parts= part_info->get_tot_partitions(); uint i, part_id; uint sub_part= no_parts; uint32 part_part= no_parts; KEY *key_info= NULL; bool found_part_field= FALSE; DBUG_ENTER("get_partition_set"); part_spec->start_part= 0; part_spec->end_part= no_parts - 1; if ((index < MAX_KEY) && key_spec->flag == (uint)HA_READ_KEY_EXACT && part_info->some_fields_in_PF.is_set(index)) { key_info= table->key_info+index; /* The index can potentially provide at least one PF-field (field in the partition function). Thus it is interesting to continue our probe. */ if (key_spec->length == key_info->key_length) { /* The entire key is set so we can check whether we can immediately derive either the complete PF or if we can derive either the top PF or the subpartitioning PF. This can be established by checking precalculated bits on each index. */ if (part_info->all_fields_in_PF.is_set(index)) { /* We can derive the exact partition to use, no more than this one is needed. */ get_full_part_id_from_key(table,buf,key_info,key_spec,part_spec); /* Check if range can be adjusted by looking in used_partitions */ prune_partition_set(table, part_spec); DBUG_VOID_RETURN; } else if (part_info->is_sub_partitioned()) { if (part_info->all_fields_in_SPF.is_set(index)) { if (get_sub_part_id_from_key(table, buf, key_info, key_spec, &sub_part)) { part_spec->start_part= no_parts; DBUG_VOID_RETURN; } } else if (part_info->all_fields_in_PPF.is_set(index)) { if (get_part_id_from_key(table,buf,key_info, key_spec,(uint32*)&part_part)) { /* The value of the RANGE or LIST partitioning was outside of allowed values. Thus it is certain that the result of this scan will be empty. */ part_spec->start_part= no_parts; DBUG_VOID_RETURN; } } } } else { /* Set an indicator on all partition fields that are bound. If at least one PF-field was bound it pays off to check whether the PF or PPF or SPF has been bound. (PF = Partition Function, SPF = Subpartition Function and PPF = Partition Function part of subpartitioning) */ if ((found_part_field= set_PF_fields_in_key(key_info, key_spec->length))) { if (check_part_func_bound(part_info->full_part_field_array)) { /* We were able to bind all fields in the partition function even by using only a part of the key. Calculate the partition to use. */ get_full_part_id_from_key(table,buf,key_info,key_spec,part_spec); clear_indicator_in_key_fields(key_info); /* Check if range can be adjusted by looking in used_partitions */ prune_partition_set(table, part_spec); DBUG_VOID_RETURN; } else if (part_info->is_sub_partitioned()) { if (check_part_func_bound(part_info->subpart_field_array)) { if (get_sub_part_id_from_key(table, buf, key_info, key_spec, &sub_part)) { part_spec->start_part= no_parts; clear_indicator_in_key_fields(key_info); DBUG_VOID_RETURN; } } else if (check_part_func_bound(part_info->part_field_array)) { if (get_part_id_from_key(table,buf,key_info,key_spec,&part_part)) { part_spec->start_part= no_parts; clear_indicator_in_key_fields(key_info); DBUG_VOID_RETURN; } } } } } } { /* The next step is to analyse the table condition to see whether any information about which partitions to scan can be derived from there. Currently not implemented. */ } /* If we come here we have found a range of sorts we have either discovered nothing or we have discovered a range of partitions with possible holes in it. We need a bitvector to further the work here. */ if (!(part_part == no_parts && sub_part == no_parts)) { /* We can only arrive here if we are using subpartitioning. */ if (part_part != no_parts) { /* We know the top partition and need to scan all underlying subpartitions. This is a range without holes. */ DBUG_ASSERT(sub_part == no_parts); part_spec->start_part= part_part * part_info->no_subparts; part_spec->end_part= part_spec->start_part+part_info->no_subparts - 1; } else { DBUG_ASSERT(sub_part != no_parts); part_spec->start_part= sub_part; part_spec->end_part=sub_part+ (part_info->no_subparts*(part_info->no_parts-1)); for (i= 0, part_id= sub_part; i < part_info->no_parts; i++, part_id+= part_info->no_subparts) ; //Set bit part_id in bit array } } if (found_part_field) clear_indicator_in_key_fields(key_info); /* Check if range can be adjusted by looking in used_partitions */ prune_partition_set(table, part_spec); DBUG_VOID_RETURN; } /* If the table is partitioned we will read the partition info into the .frm file here. ------------------------------- | Fileinfo 64 bytes | ------------------------------- | Formnames 7 bytes | ------------------------------- | Not used 4021 bytes | ------------------------------- | Keyinfo + record | ------------------------------- | Padded to next multiple | | of IO_SIZE | ------------------------------- | Forminfo 288 bytes | ------------------------------- | Screen buffer, to make | |field names readable | ------------------------------- | Packed field info | |17 + 1 + strlen(field_name) | | + 1 end of file character | ------------------------------- | Partition info | ------------------------------- We provide the length of partition length in Fileinfo[55-58]. Read the partition syntax from the frm file and parse it to get the data structures of the partitioning. SYNOPSIS mysql_unpack_partition() thd Thread object part_buf Partition info from frm file part_info_len Length of partition syntax table Table object of partitioned table create_table_ind Is it called from CREATE TABLE default_db_type What is the default engine of the table work_part_info_used Flag is raised if we don't create new part_info, but used thd->work_part_info RETURN VALUE TRUE Error FALSE Sucess DESCRIPTION Read the partition syntax from the current position in the frm file. Initiate a LEX object, save the list of item tree objects to free after the query is done. Set-up partition info object such that parser knows it is called from internally. Call parser to create data structures (best possible recreation of item trees and so forth since there is no serialisation of these objects other than in parseable text format). We need to save the text of the partition functions since it is not possible to retrace this given an item tree. */ bool mysql_unpack_partition(THD *thd, const char *part_buf, uint part_info_len, const char *part_state, uint part_state_len, TABLE* table, bool is_create_table_ind, handlerton *default_db_type, bool *work_part_info_used) { bool result= TRUE; partition_info *part_info; CHARSET_INFO *old_character_set_client= thd->variables.character_set_client; LEX *old_lex= thd->lex; LEX lex; DBUG_ENTER("mysql_unpack_partition"); thd->lex= &lex; thd->variables.character_set_client= system_charset_info; Parser_state parser_state(thd, part_buf, part_info_len); lex_start(thd); *work_part_info_used= false; /* We need to use the current SELECT_LEX since I need to keep the Name_resolution_context object which is referenced from the Item_field objects. This is not a nice solution since if the parser uses current_select for anything else it will corrupt the current LEX object. */ thd->lex->current_select= old_lex->current_select; /* All Items created is put into a free list on the THD object. This list is used to free all Item objects after completing a query. We don't want that to happen with the Item tree created as part of the partition info. This should be attached to the table object and remain so until the table object is released. Thus we move away the current list temporarily and start a new list that we then save in the partition info structure. */ lex.part_info= new partition_info();/* Indicates MYSQLparse from this place */ if (!lex.part_info) { mem_alloc_error(sizeof(partition_info)); goto end; } lex.part_info->part_state= part_state; lex.part_info->part_state_len= part_state_len; DBUG_PRINT("info", ("Parse: %s", part_buf)); if (parse_sql(thd, & parser_state, NULL)) { thd->free_items(); goto end; } /* The parsed syntax residing in the frm file can still contain defaults. The reason is that the frm file is sometimes saved outside of this MySQL Server and used in backup and restore of clusters or partitioned tables. It is not certain that the restore will restore exactly the same default partitioning. The easiest manner of handling this is to simply continue using the part_info we already built up during mysql_create_table if we are in the process of creating a table. If the table already exists we need to discover the number of partitions for the default parts. Since the handler object hasn't been created here yet we need to postpone this to the fix_partition_func method. */ DBUG_PRINT("info", ("Successful parse")); part_info= lex.part_info; DBUG_PRINT("info", ("default engine = %s, default_db_type = %s", ha_resolve_storage_engine_name(part_info->default_engine_type), ha_resolve_storage_engine_name(default_db_type))); if (is_create_table_ind && old_lex->sql_command == SQLCOM_CREATE_TABLE) { if (old_lex->create_info.options & HA_LEX_CREATE_TABLE_LIKE) { /* This code is executed when we create table in CREATE TABLE t1 LIKE t2. old_lex->query_tables contains table list element for t2 and the table we are opening has name t1. */ if (partition_default_handling(table, part_info, FALSE, old_lex->query_tables->table->s->path.str)) { result= TRUE; goto end; } } else { /* When we come here we are doing a create table. In this case we have already done some preparatory work on the old part_info object. We don't really need this new partition_info object. Thus we go back to the old partition info object. We need to free any memory objects allocated on item_free_list by the parser since we are keeping the old info from the first parser call in CREATE TABLE. We'll ensure that this object isn't put into table cache also just to ensure we don't get into strange situations with the item objects. */ thd->free_items(); part_info= thd->work_part_info; table->s->version= 0UL; *work_part_info_used= true; } } table->part_info= part_info; table->file->set_part_info(part_info); if (!part_info->default_engine_type) part_info->default_engine_type= default_db_type; DBUG_ASSERT(part_info->default_engine_type == default_db_type); DBUG_ASSERT(part_info->default_engine_type->db_type != DB_TYPE_UNKNOWN); DBUG_ASSERT(part_info->default_engine_type != partition_hton); { /* This code part allocates memory for the serialised item information for the partition functions. In most cases this is not needed but if the table is used for SHOW CREATE TABLES or ALTER TABLE that modifies partition information it is needed and the info is lost if we don't save it here so unfortunately we have to do it here even if in most cases it is not needed. This is a consequence of that item trees are not serialisable. */ uint part_func_len= part_info->part_func_len; uint subpart_func_len= part_info->subpart_func_len; char *part_func_string= NULL; char *subpart_func_string= NULL; if ((part_func_len && !((part_func_string= (char*) thd->alloc(part_func_len)))) || (subpart_func_len && !((subpart_func_string= (char*) thd->alloc(subpart_func_len))))) { mem_alloc_error(part_func_len); thd->free_items(); goto end; } if (part_func_len) memcpy(part_func_string, part_info->part_func_string, part_func_len); if (subpart_func_len) memcpy(subpart_func_string, part_info->subpart_func_string, subpart_func_len); part_info->part_func_string= part_func_string; part_info->subpart_func_string= subpart_func_string; } result= FALSE; end: lex_end(thd->lex); thd->lex= old_lex; thd->variables.character_set_client= old_character_set_client; DBUG_RETURN(result); } /* Set engine type on all partition element objects SYNOPSIS set_engine_all_partitions() part_info Partition info engine_type Handlerton reference of engine RETURN VALUES NONE */ static void set_engine_all_partitions(partition_info *part_info, handlerton *engine_type) { uint i= 0; List_iterator part_it(part_info->partitions); do { partition_element *part_elem= part_it++; part_elem->engine_type= engine_type; if (part_info->is_sub_partitioned()) { List_iterator sub_it(part_elem->subpartitions); uint j= 0; do { partition_element *sub_elem= sub_it++; sub_elem->engine_type= engine_type; } while (++j < part_info->no_subparts); } } while (++i < part_info->no_parts); } /* SYNOPSIS fast_end_partition() thd Thread object out:copied Number of records copied out:deleted Number of records deleted table_list Table list with the one table in it empty Has nothing been done lpt Struct to be used by error handler RETURN VALUES FALSE Success TRUE Failure DESCRIPTION Support routine to handle the successful cases for partition management. */ static int fast_end_partition(THD *thd, ulonglong copied, ulonglong deleted, TABLE *table, TABLE_LIST *table_list, bool is_empty, ALTER_PARTITION_PARAM_TYPE *lpt, bool written_bin_log) { int error; char tmp_name[80]; DBUG_ENTER("fast_end_partition"); thd->proc_info="end"; if (!is_empty) query_cache_invalidate3(thd, table_list, 0); error= ha_autocommit_or_rollback(thd, 0); if (end_active_trans(thd)) error= 1; if (error) { /* If error during commit, no need to rollback, it's done. */ table->file->print_error(error, MYF(0)); DBUG_RETURN(TRUE); } if ((!is_empty) && (!written_bin_log) && (!thd->lex->no_write_to_binlog)) write_bin_log(thd, FALSE, thd->query, thd->query_length); my_snprintf(tmp_name, sizeof(tmp_name), ER(ER_INSERT_INFO), (ulong) (copied + deleted), (ulong) deleted, (ulong) 0); my_ok(thd, (ha_rows) (copied+deleted),0L, tmp_name); DBUG_RETURN(FALSE); } /* We need to check if engine used by all partitions can handle partitioning natively. SYNOPSIS check_native_partitioned() create_info Create info in CREATE TABLE out:ret_val Return value part_info Partition info thd Thread object RETURN VALUES Value returned in bool ret_value TRUE Native partitioning supported by engine FALSE Need to use partition handler Return value from function TRUE Error FALSE Success */ static bool check_native_partitioned(HA_CREATE_INFO *create_info,bool *ret_val, partition_info *part_info, THD *thd) { bool table_engine_set; handlerton *engine_type= part_info->default_engine_type; handlerton *old_engine_type= engine_type; DBUG_ENTER("check_native_partitioned"); if (create_info->used_fields & HA_CREATE_USED_ENGINE) { table_engine_set= TRUE; engine_type= create_info->db_type; } else { table_engine_set= FALSE; if (thd->lex->sql_command != SQLCOM_CREATE_TABLE) { table_engine_set= TRUE; DBUG_ASSERT(engine_type && engine_type != partition_hton); } } DBUG_PRINT("info", ("engine_type = %s, table_engine_set = %u", ha_resolve_storage_engine_name(engine_type), table_engine_set)); if (part_info->check_engine_mix(engine_type, table_engine_set)) goto error; /* All engines are of the same type. Check if this engine supports native partitioning. */ if (!engine_type) engine_type= old_engine_type; DBUG_PRINT("info", ("engine_type = %s", ha_resolve_storage_engine_name(engine_type))); if (engine_type->partition_flags && (engine_type->partition_flags() & HA_CAN_PARTITION)) { create_info->db_type= engine_type; DBUG_PRINT("info", ("Changed to native partitioning")); *ret_val= TRUE; } DBUG_RETURN(FALSE); error: /* Mixed engines not yet supported but when supported it will need the partition handler */ my_error(ER_MIX_HANDLER_ERROR, MYF(0)); *ret_val= FALSE; DBUG_RETURN(TRUE); } /* Sets which partitions to be used in the command */ uint set_part_state(Alter_info *alter_info, partition_info *tab_part_info, enum partition_state part_state) { uint part_count= 0; uint no_parts_found= 0; List_iterator part_it(tab_part_info->partitions); do { partition_element *part_elem= part_it++; if ((alter_info->flags & ALTER_ALL_PARTITION) || (is_name_in_list(part_elem->partition_name, alter_info->partition_names))) { /* Mark the partition. I.e mark the partition as a partition to be "changed" by analyzing/optimizing/rebuilding/checking/repairing */ no_parts_found++; part_elem->part_state= part_state; DBUG_PRINT("info", ("Setting part_state to %u for partition %s", part_state, part_elem->partition_name)); } } while (++part_count < tab_part_info->no_parts); return no_parts_found; } /* Prepare for ALTER TABLE of partition structure SYNOPSIS prep_alter_part_table() thd Thread object table Table object inout:alter_info Alter information inout:create_info Create info for CREATE TABLE old_db_type Old engine type out:partition_changed Boolean indicating whether partition changed out:fast_alter_partition Boolean indicating whether fast partition change is requested RETURN VALUES TRUE Error FALSE Success partition_changed fast_alter_partition DESCRIPTION This method handles all preparations for ALTER TABLE for partitioned tables We need to handle both partition management command such as Add Partition and others here as well as an ALTER TABLE that completely changes the partitioning and yet others that don't change anything at all. We start by checking the partition management variants and then check the general change patterns. */ uint prep_alter_part_table(THD *thd, TABLE *table, Alter_info *alter_info, HA_CREATE_INFO *create_info, handlerton *old_db_type, bool *partition_changed, uint *fast_alter_partition) { DBUG_ENTER("prep_alter_part_table"); /* We are going to manipulate the partition info on the table object so we need to ensure that the data structure of the table object is freed by setting version to 0. table->s->version= 0 forces a flush of the table object in close_thread_tables(). */ if (table->part_info) table->s->version= 0L; thd->work_part_info= thd->lex->part_info; if (thd->work_part_info && !(thd->work_part_info= thd->lex->part_info->get_clone())) DBUG_RETURN(TRUE); /* ALTER_ADMIN_PARTITION is handled in mysql_admin_table */ DBUG_ASSERT(!(alter_info->flags & ALTER_ADMIN_PARTITION)); if (alter_info->flags & (ALTER_ADD_PARTITION | ALTER_DROP_PARTITION | ALTER_COALESCE_PARTITION | ALTER_REORGANIZE_PARTITION | ALTER_TABLE_REORG | ALTER_REBUILD_PARTITION)) { partition_info *tab_part_info= table->part_info; partition_info *alt_part_info= thd->work_part_info; uint flags= 0; if (!tab_part_info) { my_error(ER_PARTITION_MGMT_ON_NONPARTITIONED, MYF(0)); DBUG_RETURN(TRUE); } if (alter_info->flags & ALTER_TABLE_REORG) { uint new_part_no, curr_part_no; if (tab_part_info->part_type != HASH_PARTITION || tab_part_info->use_default_no_partitions) { my_error(ER_REORG_NO_PARAM_ERROR, MYF(0)); DBUG_RETURN(TRUE); } new_part_no= table->file->get_default_no_partitions(create_info); curr_part_no= tab_part_info->no_parts; if (new_part_no == curr_part_no) { /* No change is needed, we will have the same number of partitions after the change as before. Thus we can reply ok immediately without any changes at all. */ *fast_alter_partition= TRUE; DBUG_RETURN(FALSE); } else if (new_part_no > curr_part_no) { /* We will add more partitions, we use the ADD PARTITION without setting the flag for no default number of partitions */ alter_info->flags|= ALTER_ADD_PARTITION; thd->work_part_info->no_parts= new_part_no - curr_part_no; } else { /* We will remove hash partitions, we use the COALESCE PARTITION without setting the flag for no default number of partitions */ alter_info->flags|= ALTER_COALESCE_PARTITION; alter_info->no_parts= curr_part_no - new_part_no; } } if (!(flags= table->file->alter_table_flags(alter_info->flags))) { my_error(ER_PARTITION_FUNCTION_FAILURE, MYF(0)); DBUG_RETURN(1); } *fast_alter_partition= ((flags & (HA_FAST_CHANGE_PARTITION | HA_PARTITION_ONE_PHASE)) != 0); DBUG_PRINT("info", ("*fast_alter_partition: %d flags: 0x%x", *fast_alter_partition, flags)); if (((alter_info->flags & ALTER_ADD_PARTITION) || (alter_info->flags & ALTER_REORGANIZE_PARTITION)) && (thd->work_part_info->part_type != tab_part_info->part_type) && (thd->work_part_info->part_type != NOT_A_PARTITION)) { if (thd->work_part_info->part_type == RANGE_PARTITION) { my_error(ER_PARTITION_WRONG_VALUES_ERROR, MYF(0), "RANGE", "LESS THAN"); } else if (thd->work_part_info->part_type == LIST_PARTITION) { DBUG_ASSERT(thd->work_part_info->part_type == LIST_PARTITION); my_error(ER_PARTITION_WRONG_VALUES_ERROR, MYF(0), "LIST", "IN"); } else if (tab_part_info->part_type == RANGE_PARTITION) { my_error(ER_PARTITION_REQUIRES_VALUES_ERROR, MYF(0), "RANGE", "LESS THAN"); } else { DBUG_ASSERT(tab_part_info->part_type == LIST_PARTITION); my_error(ER_PARTITION_REQUIRES_VALUES_ERROR, MYF(0), "LIST", "IN"); } DBUG_RETURN(TRUE); } if (alter_info->flags & ALTER_ADD_PARTITION) { /* We start by moving the new partitions to the list of temporary partitions. We will then check that the new partitions fit in the partitioning scheme as currently set-up. Partitions are always added at the end in ADD PARTITION. */ uint no_new_partitions= alt_part_info->no_parts; uint no_orig_partitions= tab_part_info->no_parts; uint check_total_partitions= no_new_partitions + no_orig_partitions; uint new_total_partitions= check_total_partitions; /* We allow quite a lot of values to be supplied by defaults, however we must know the number of new partitions in this case. */ if (thd->lex->no_write_to_binlog && tab_part_info->part_type != HASH_PARTITION) { my_error(ER_NO_BINLOG_ERROR, MYF(0)); DBUG_RETURN(TRUE); } if (tab_part_info->defined_max_value) { my_error(ER_PARTITION_MAXVALUE_ERROR, MYF(0)); DBUG_RETURN(TRUE); } if (no_new_partitions == 0) { my_error(ER_ADD_PARTITION_NO_NEW_PARTITION, MYF(0)); DBUG_RETURN(TRUE); } if (tab_part_info->is_sub_partitioned()) { if (alt_part_info->no_subparts == 0) alt_part_info->no_subparts= tab_part_info->no_subparts; else if (alt_part_info->no_subparts != tab_part_info->no_subparts) { my_error(ER_ADD_PARTITION_SUBPART_ERROR, MYF(0)); DBUG_RETURN(TRUE); } check_total_partitions= new_total_partitions* alt_part_info->no_subparts; } if (check_total_partitions > MAX_PARTITIONS) { my_error(ER_TOO_MANY_PARTITIONS_ERROR, MYF(0)); DBUG_RETURN(TRUE); } alt_part_info->part_type= tab_part_info->part_type; alt_part_info->subpart_type= tab_part_info->subpart_type; if (alt_part_info->set_up_defaults_for_partitioning(table->file, ULL(0), tab_part_info->no_parts)) { DBUG_RETURN(TRUE); } /* Handling of on-line cases: ADD PARTITION for RANGE/LIST PARTITIONING: ------------------------------------------ For range and list partitions add partition is simply adding a new empty partition to the table. If the handler support this we will use the simple method of doing this. The figure below shows an example of this and the states involved in making this change. Existing partitions New added partitions ------ ------ ------ ------ | ------ ------ | | | | | | | | | | | | | | p0 | | p1 | | p2 | | p3 | | | p4 | | p5 | ------ ------ ------ ------ | ------ ------ PART_NORMAL PART_NORMAL PART_NORMAL PART_NORMAL PART_TO_BE_ADDED*2 PART_NORMAL PART_NORMAL PART_NORMAL PART_NORMAL PART_IS_ADDED*2 The first line is the states before adding the new partitions and the second line is after the new partitions are added. All the partitions are in the partitions list, no partitions are placed in the temp_partitions list. ADD PARTITION for HASH PARTITIONING ----------------------------------- This little figure tries to show the various partitions involved when adding two new partitions to a linear hash based partitioned table with four partitions to start with, which lists are used and the states they pass through. Adding partitions to a normal hash based is similar except that it is always all the existing partitions that are reorganised not only a subset of them. Existing partitions New added partitions ------ ------ ------ ------ | ------ ------ | | | | | | | | | | | | | | p0 | | p1 | | p2 | | p3 | | | p4 | | p5 | ------ ------ ------ ------ | ------ ------ PART_CHANGED PART_CHANGED PART_NORMAL PART_NORMAL PART_TO_BE_ADDED PART_IS_CHANGED*2 PART_NORMAL PART_NORMAL PART_IS_ADDED PART_NORMAL PART_NORMAL PART_NORMAL PART_NORMAL PART_IS_ADDED Reorganised existing partitions ------ ------ | | | | | p0'| | p1'| ------ ------ p0 - p5 will be in the partitions list of partitions. p0' and p1' will actually not exist as separate objects, there presence can be deduced from the state of the partition and also the names of those partitions can be deduced this way. After adding the partitions and copying the partition data to p0', p1', p4 and p5 from p0 and p1 the states change to adapt for the new situation where p0 and p1 is dropped and replaced by p0' and p1' and the new p4 and p5 are in the table again. The first line above shows the states of the partitions before we start adding and copying partitions, the second after completing the adding and copying and finally the third line after also dropping the partitions that are reorganised. */ if (*fast_alter_partition && tab_part_info->part_type == HASH_PARTITION) { uint part_no= 0, start_part= 1, start_sec_part= 1; uint end_part= 0, end_sec_part= 0; uint upper_2n= tab_part_info->linear_hash_mask + 1; uint lower_2n= upper_2n >> 1; bool all_parts= TRUE; if (tab_part_info->linear_hash_ind && no_new_partitions < upper_2n) { /* An analysis of which parts needs reorganisation shows that it is divided into two intervals. The first interval is those parts that are reorganised up until upper_2n - 1. From upper_2n and onwards it starts again from partition 0 and goes on until it reaches p(upper_2n - 1). If the last new partition reaches beyond upper_2n - 1 then the first interval will end with p(lower_2n - 1) and start with p(no_orig_partitions - lower_2n). If lower_2n partitions are added then p0 to p(lower_2n - 1) will be reorganised which means that the two interval becomes one interval at this point. Thus only when adding less than lower_2n partitions and going beyond a total of upper_2n we actually get two intervals. To exemplify this assume we have 6 partitions to start with and add 1, 2, 3, 5, 6, 7, 8, 9 partitions. The first to add after p5 is p6 = 110 in bit numbers. Thus we can see that 10 = p2 will be partition to reorganise if only one partition. If 2 partitions are added we reorganise [p2, p3]. Those two cases are covered by the second if part below. If 3 partitions are added we reorganise [p2, p3] U [p0,p0]. This part is covered by the else part below. If 5 partitions are added we get [p2,p3] U [p0, p2] = [p0, p3]. This is covered by the first if part where we need the max check to here use lower_2n - 1. If 7 partitions are added we get [p2,p3] U [p0, p4] = [p0, p4]. This is covered by the first if part but here we use the first calculated end_part. Finally with 9 new partitions we would also reorganise p6 if we used the method below but we cannot reorganise more partitions than what we had from the start and thus we simply set all_parts to TRUE. In this case we don't get into this if-part at all. */ all_parts= FALSE; if (no_new_partitions >= lower_2n) { /* In this case there is only one interval since the two intervals overlap and this starts from zero to last_part_no - upper_2n */ start_part= 0; end_part= new_total_partitions - (upper_2n + 1); end_part= max(lower_2n - 1, end_part); } else if (new_total_partitions <= upper_2n) { /* Also in this case there is only one interval since we are not going over a 2**n boundary */ start_part= no_orig_partitions - lower_2n; end_part= start_part + (no_new_partitions - 1); } else { /* We have two non-overlapping intervals since we are not passing a 2**n border and we have not at least lower_2n new parts that would ensure that the intervals become overlapping. */ start_part= no_orig_partitions - lower_2n; end_part= upper_2n - 1; start_sec_part= 0; end_sec_part= new_total_partitions - (upper_2n + 1); } } List_iterator tab_it(tab_part_info->partitions); part_no= 0; do { partition_element *p_elem= tab_it++; if (all_parts || (part_no >= start_part && part_no <= end_part) || (part_no >= start_sec_part && part_no <= end_sec_part)) { p_elem->part_state= PART_CHANGED; } } while (++part_no < no_orig_partitions); } /* Need to concatenate the lists here to make it possible to check the partition info for correctness using check_partition_info. For on-line add partition we set the state of this partition to PART_TO_BE_ADDED to ensure that it is known that it is not yet usable (becomes usable when partition is created and the switch of partition configuration is made. */ { List_iterator alt_it(alt_part_info->partitions); uint part_count= 0; do { partition_element *part_elem= alt_it++; if (*fast_alter_partition) part_elem->part_state= PART_TO_BE_ADDED; if (tab_part_info->partitions.push_back(part_elem)) { mem_alloc_error(1); DBUG_RETURN(TRUE); } } while (++part_count < no_new_partitions); tab_part_info->no_parts+= no_new_partitions; } /* If we specify partitions explicitly we don't use defaults anymore. Using ADD PARTITION also means that we don't have the default number of partitions anymore. We use this code also for Table reorganisations and here we don't set any default flags to FALSE. */ if (!(alter_info->flags & ALTER_TABLE_REORG)) { if (!alt_part_info->use_default_partitions) { DBUG_PRINT("info", ("part_info: 0x%lx", (long) tab_part_info)); tab_part_info->use_default_partitions= FALSE; } tab_part_info->use_default_no_partitions= FALSE; tab_part_info->is_auto_partitioned= FALSE; } } else if (alter_info->flags & ALTER_DROP_PARTITION) { /* Drop a partition from a range partition and list partitioning is always safe and can be made more or less immediate. It is necessary however to ensure that the partition to be removed is safely removed and that REPAIR TABLE can remove the partition if for some reason the command to drop the partition failed in the middle. */ uint part_count= 0; uint no_parts_dropped= alter_info->partition_names.elements; uint no_parts_found= 0; List_iterator part_it(tab_part_info->partitions); tab_part_info->is_auto_partitioned= FALSE; if (!(tab_part_info->part_type == RANGE_PARTITION || tab_part_info->part_type == LIST_PARTITION)) { my_error(ER_ONLY_ON_RANGE_LIST_PARTITION, MYF(0), "DROP"); DBUG_RETURN(TRUE); } if (no_parts_dropped >= tab_part_info->no_parts) { my_error(ER_DROP_LAST_PARTITION, MYF(0)); DBUG_RETURN(TRUE); } do { partition_element *part_elem= part_it++; if (is_name_in_list(part_elem->partition_name, alter_info->partition_names)) { /* Set state to indicate that the partition is to be dropped. */ no_parts_found++; part_elem->part_state= PART_TO_BE_DROPPED; } } while (++part_count < tab_part_info->no_parts); if (no_parts_found != no_parts_dropped) { my_error(ER_DROP_PARTITION_NON_EXISTENT, MYF(0), "DROP"); DBUG_RETURN(TRUE); } if (table->file->is_fk_defined_on_table_or_index(MAX_KEY)) { my_error(ER_ROW_IS_REFERENCED, MYF(0)); DBUG_RETURN(TRUE); } tab_part_info->no_parts-= no_parts_dropped; } else if (alter_info->flags & ALTER_REBUILD_PARTITION) { uint no_parts_found; uint no_parts_opt= alter_info->partition_names.elements; no_parts_found= set_part_state(alter_info, tab_part_info, PART_CHANGED); if (no_parts_found != no_parts_opt && (!(alter_info->flags & ALTER_ALL_PARTITION))) { my_error(ER_DROP_PARTITION_NON_EXISTENT, MYF(0), "REBUILD"); DBUG_RETURN(TRUE); } if (!(*fast_alter_partition)) { table->file->print_error(HA_ERR_WRONG_COMMAND, MYF(0)); DBUG_RETURN(TRUE); } } else if (alter_info->flags & ALTER_COALESCE_PARTITION) { uint no_parts_coalesced= alter_info->no_parts; uint no_parts_remain= tab_part_info->no_parts - no_parts_coalesced; List_iterator part_it(tab_part_info->partitions); if (tab_part_info->part_type != HASH_PARTITION) { my_error(ER_COALESCE_ONLY_ON_HASH_PARTITION, MYF(0)); DBUG_RETURN(TRUE); } if (no_parts_coalesced == 0) { my_error(ER_COALESCE_PARTITION_NO_PARTITION, MYF(0)); DBUG_RETURN(TRUE); } if (no_parts_coalesced >= tab_part_info->no_parts) { my_error(ER_DROP_LAST_PARTITION, MYF(0)); DBUG_RETURN(TRUE); } /* Online handling: COALESCE PARTITION: ------------------- The figure below shows the manner in which partitions are handled when performing an on-line coalesce partition and which states they go through at start, after adding and copying partitions and finally after dropping the partitions to drop. The figure shows an example using four partitions to start with, using linear hash and coalescing one partition (always the last partition). Using linear hash then all remaining partitions will have a new reorganised part. Existing partitions Coalesced partition ------ ------ ------ | ------ | | | | | | | | | | p0 | | p1 | | p2 | | | p3 | ------ ------ ------ | ------ PART_NORMAL PART_CHANGED PART_NORMAL PART_REORGED_DROPPED PART_NORMAL PART_IS_CHANGED PART_NORMAL PART_TO_BE_DROPPED PART_NORMAL PART_NORMAL PART_NORMAL PART_IS_DROPPED Reorganised existing partitions ------ | | | p1'| ------ p0 - p3 is in the partitions list. The p1' partition will actually not be in any list it is deduced from the state of p1. */ { uint part_count= 0, start_part= 1, start_sec_part= 1; uint end_part= 0, end_sec_part= 0; bool all_parts= TRUE; if (*fast_alter_partition && tab_part_info->linear_hash_ind) { uint upper_2n= tab_part_info->linear_hash_mask + 1; uint lower_2n= upper_2n >> 1; all_parts= FALSE; if (no_parts_coalesced >= lower_2n) { all_parts= TRUE; } else if (no_parts_remain >= lower_2n) { end_part= tab_part_info->no_parts - (lower_2n + 1); start_part= no_parts_remain - lower_2n; } else { start_part= 0; end_part= tab_part_info->no_parts - (lower_2n + 1); end_sec_part= (lower_2n >> 1) - 1; start_sec_part= end_sec_part - (lower_2n - (no_parts_remain + 1)); } } do { partition_element *p_elem= part_it++; if (*fast_alter_partition && (all_parts || (part_count >= start_part && part_count <= end_part) || (part_count >= start_sec_part && part_count <= end_sec_part))) p_elem->part_state= PART_CHANGED; if (++part_count > no_parts_remain) { if (*fast_alter_partition) p_elem->part_state= PART_REORGED_DROPPED; else part_it.remove(); } } while (part_count < tab_part_info->no_parts); tab_part_info->no_parts= no_parts_remain; } if (!(alter_info->flags & ALTER_TABLE_REORG)) { tab_part_info->use_default_no_partitions= FALSE; tab_part_info->is_auto_partitioned= FALSE; } } else if (alter_info->flags & ALTER_REORGANIZE_PARTITION) { /* Reorganise partitions takes a number of partitions that are next to each other (at least for RANGE PARTITIONS) and then uses those to create a set of new partitions. So data is copied from those partitions into the new set of partitions. Those new partitions can have more values in the LIST value specifications or less both are allowed. The ranges can be different but since they are changing a set of consecutive partitions they must cover the same range as those changed from. This command can be used on RANGE and LIST partitions. */ uint no_parts_reorged= alter_info->partition_names.elements; uint no_parts_new= thd->work_part_info->partitions.elements; partition_info *alt_part_info= thd->work_part_info; uint check_total_partitions; tab_part_info->is_auto_partitioned= FALSE; if (no_parts_reorged > tab_part_info->no_parts) { my_error(ER_REORG_PARTITION_NOT_EXIST, MYF(0)); DBUG_RETURN(TRUE); } if (!(tab_part_info->part_type == RANGE_PARTITION || tab_part_info->part_type == LIST_PARTITION) && (no_parts_new != no_parts_reorged)) { my_error(ER_REORG_HASH_ONLY_ON_SAME_NO, MYF(0)); DBUG_RETURN(TRUE); } if (tab_part_info->is_sub_partitioned() && alt_part_info->no_subparts && alt_part_info->no_subparts != tab_part_info->no_subparts) { my_error(ER_PARTITION_WRONG_NO_SUBPART_ERROR, MYF(0)); DBUG_RETURN(TRUE); } check_total_partitions= tab_part_info->no_parts + no_parts_new; check_total_partitions-= no_parts_reorged; if (check_total_partitions > MAX_PARTITIONS) { my_error(ER_TOO_MANY_PARTITIONS_ERROR, MYF(0)); DBUG_RETURN(TRUE); } alt_part_info->part_type= tab_part_info->part_type; alt_part_info->subpart_type= tab_part_info->subpart_type; alt_part_info->no_subparts= tab_part_info->no_subparts; DBUG_ASSERT(!alt_part_info->use_default_partitions); if (alt_part_info->set_up_defaults_for_partitioning(table->file, ULL(0), 0)) { DBUG_RETURN(TRUE); } /* Online handling: REORGANIZE PARTITION: --------------------- The figure exemplifies the handling of partitions, their state changes and how they are organised. It exemplifies four partitions where two of the partitions are reorganised (p1 and p2) into two new partitions (p4 and p5). The reason of this change could be to change range limits, change list values or for hash partitions simply reorganise the partition which could also involve moving them to new disks or new node groups (MySQL Cluster). Existing partitions ------ ------ ------ ------ | | | | | | | | | p0 | | p1 | | p2 | | p3 | ------ ------ ------ ------ PART_NORMAL PART_TO_BE_REORGED PART_NORMAL PART_NORMAL PART_TO_BE_DROPPED PART_NORMAL PART_NORMAL PART_IS_DROPPED PART_NORMAL Reorganised new partitions (replacing p1 and p2) ------ ------ | | | | | p4 | | p5 | ------ ------ PART_TO_BE_ADDED PART_IS_ADDED PART_IS_ADDED All unchanged partitions and the new partitions are in the partitions list in the order they will have when the change is completed. The reorganised partitions are placed in the temp_partitions list. PART_IS_ADDED is only a temporary state not written in the frm file. It is used to ensure we write the generated partition syntax in a correct manner. */ { List_iterator tab_it(tab_part_info->partitions); uint part_count= 0; bool found_first= FALSE; bool found_last= FALSE; bool is_last_partition_reorged; uint drop_count= 0; longlong tab_max_range= 0, alt_max_range= 0; do { partition_element *part_elem= tab_it++; is_last_partition_reorged= FALSE; if (is_name_in_list(part_elem->partition_name, alter_info->partition_names)) { is_last_partition_reorged= TRUE; drop_count++; tab_max_range= part_elem->range_value; if (*fast_alter_partition && tab_part_info->temp_partitions.push_back(part_elem)) { mem_alloc_error(1); DBUG_RETURN(TRUE); } if (*fast_alter_partition) part_elem->part_state= PART_TO_BE_REORGED; if (!found_first) { uint alt_part_count= 0; found_first= TRUE; List_iterator alt_it(alt_part_info->partitions); do { partition_element *alt_part_elem= alt_it++; alt_max_range= alt_part_elem->range_value; if (*fast_alter_partition) alt_part_elem->part_state= PART_TO_BE_ADDED; if (alt_part_count == 0) tab_it.replace(alt_part_elem); else tab_it.after(alt_part_elem); } while (++alt_part_count < no_parts_new); } else if (found_last) { my_error(ER_CONSECUTIVE_REORG_PARTITIONS, MYF(0)); DBUG_RETURN(TRUE); } else tab_it.remove(); } else { if (found_first) found_last= TRUE; } } while (++part_count < tab_part_info->no_parts); if (drop_count != no_parts_reorged) { my_error(ER_DROP_PARTITION_NON_EXISTENT, MYF(0), "REORGANIZE"); DBUG_RETURN(TRUE); } if (tab_part_info->part_type == RANGE_PARTITION && ((is_last_partition_reorged && alt_max_range < tab_max_range) || (!is_last_partition_reorged && alt_max_range != tab_max_range))) { /* For range partitioning the total resulting range before and after the change must be the same except in one case. This is when the last partition is reorganised, in this case it is acceptable to increase the total range. The reason is that it is not allowed to have "holes" in the middle of the ranges and thus we should not allow to reorganise to create "holes". Also we should not allow using REORGANIZE to drop data. */ my_error(ER_REORG_OUTSIDE_RANGE, MYF(0)); DBUG_RETURN(TRUE); } tab_part_info->no_parts= check_total_partitions; } } else { DBUG_ASSERT(FALSE); } *partition_changed= TRUE; thd->work_part_info= tab_part_info; if (alter_info->flags & ALTER_ADD_PARTITION || alter_info->flags & ALTER_REORGANIZE_PARTITION) { if (tab_part_info->use_default_subpartitions && !alt_part_info->use_default_subpartitions) { tab_part_info->use_default_subpartitions= FALSE; tab_part_info->use_default_no_subpartitions= FALSE; } if (tab_part_info->check_partition_info(thd, (handlerton**)NULL, table->file, ULL(0), FALSE)) { DBUG_RETURN(TRUE); } } } else { /* When thd->lex->part_info has a reference to a partition_info the ALTER TABLE contained a definition of a partitioning. Case I: If there was a partition before and there is a new one defined. We use the new partitioning. The new partitioning is already defined in the correct variable so no work is needed to accomplish this. We do however need to update partition_changed to ensure that not only the frm file is changed in the ALTER TABLE command. Case IIa: There was a partitioning before and there is no new one defined. Also the user has not specified to remove partitioning explicitly. We use the old partitioning also for the new table. We do this by assigning the partition_info from the table loaded in open_table to the partition_info struct used by mysql_create_table later in this method. Case IIb: There was a partitioning before and there is no new one defined. The user has specified explicitly to remove partitioning Since the user has specified explicitly to remove partitioning we override the old partitioning info and create a new table using the specified engine. In this case the partition also is changed. Case III: There was no partitioning before altering the table, there is partitioning defined in the altered table. Use the new partitioning. No work needed since the partitioning info is already in the correct variable. In this case we discover one case where the new partitioning is using the same partition function as the default (PARTITION BY KEY or PARTITION BY LINEAR KEY with the list of fields equal to the primary key fields OR PARTITION BY [LINEAR] KEY() for tables without primary key) Also here partition has changed and thus a new table must be created. Case IV: There was no partitioning before and no partitioning defined. Obviously no work needed. */ if (table->part_info) { if (alter_info->flags & ALTER_REMOVE_PARTITIONING) { DBUG_PRINT("info", ("Remove partitioning")); if (!(create_info->used_fields & HA_CREATE_USED_ENGINE)) { DBUG_PRINT("info", ("No explicit engine used")); create_info->db_type= table->part_info->default_engine_type; } DBUG_PRINT("info", ("New engine type: %s", ha_resolve_storage_engine_name(create_info->db_type))); thd->work_part_info= NULL; *partition_changed= TRUE; } else if (!thd->work_part_info) { /* Retain partitioning but possibly with a new storage engine beneath. */ thd->work_part_info= table->part_info; if (create_info->used_fields & HA_CREATE_USED_ENGINE && create_info->db_type != table->part_info->default_engine_type) { /* Make sure change of engine happens to all partitions. */ DBUG_PRINT("info", ("partition changed")); if (table->part_info->is_auto_partitioned) { /* If the user originally didn't specify partitioning to be used we can remove it now. */ thd->work_part_info= NULL; } else { /* Ensure that all partitions have the proper engine set-up */ set_engine_all_partitions(thd->work_part_info, create_info->db_type); } *partition_changed= TRUE; } } } if (thd->work_part_info) { partition_info *part_info= thd->work_part_info; bool is_native_partitioned= FALSE; /* Need to cater for engine types that can handle partition without using the partition handler. */ if (thd->work_part_info != table->part_info) { DBUG_PRINT("info", ("partition changed")); *partition_changed= TRUE; } /* Set up partition default_engine_type either from the create_info or from the previus table */ if (create_info->used_fields & HA_CREATE_USED_ENGINE) part_info->default_engine_type= create_info->db_type; else { if (table->part_info) part_info->default_engine_type= table->part_info->default_engine_type; else part_info->default_engine_type= create_info->db_type; } DBUG_ASSERT(part_info->default_engine_type && part_info->default_engine_type != partition_hton); if (check_native_partitioned(create_info, &is_native_partitioned, part_info, thd)) { DBUG_RETURN(TRUE); } if (!is_native_partitioned) { DBUG_ASSERT(create_info->db_type); create_info->db_type= partition_hton; } } } DBUG_RETURN(FALSE); } /* Change partitions, used to implement ALTER TABLE ADD/REORGANIZE/COALESCE partitions. This method is used to implement both single-phase and multi- phase implementations of ADD/REORGANIZE/COALESCE partitions. SYNOPSIS mysql_change_partitions() lpt Struct containing parameters RETURN VALUES TRUE Failure FALSE Success DESCRIPTION Request handler to add partitions as set in states of the partition Elements of the lpt parameters used: create_info Create information used to create partitions db Database name table_name Table name copied Output parameter where number of copied records are added deleted Output parameter where number of deleted records are added */ static bool mysql_change_partitions(ALTER_PARTITION_PARAM_TYPE *lpt) { char path[FN_REFLEN+1]; int error; handler *file= lpt->table->file; DBUG_ENTER("mysql_change_partitions"); build_table_filename(path, sizeof(path), lpt->db, lpt->table_name, "", 0); if ((error= file->ha_change_partitions(lpt->create_info, path, &lpt->copied, &lpt->deleted, lpt->pack_frm_data, lpt->pack_frm_len))) { if (error != ER_OUTOFMEMORY) file->print_error(error, MYF(0)); else lpt->thd->fatal_error(); DBUG_RETURN(TRUE); } DBUG_RETURN(FALSE); } /* Rename partitions in an ALTER TABLE of partitions SYNOPSIS mysql_rename_partitions() lpt Struct containing parameters RETURN VALUES TRUE Failure FALSE Success DESCRIPTION Request handler to rename partitions as set in states of the partition Parameters used: db Database name table_name Table name */ static bool mysql_rename_partitions(ALTER_PARTITION_PARAM_TYPE *lpt) { char path[FN_REFLEN+1]; int error; DBUG_ENTER("mysql_rename_partitions"); build_table_filename(path, sizeof(path), lpt->db, lpt->table_name, "", 0); if ((error= lpt->table->file->ha_rename_partitions(path))) { if (error != 1) lpt->table->file->print_error(error, MYF(0)); DBUG_RETURN(TRUE); } DBUG_RETURN(FALSE); } /* Drop partitions in an ALTER TABLE of partitions SYNOPSIS mysql_drop_partitions() lpt Struct containing parameters RETURN VALUES TRUE Failure FALSE Success DESCRIPTION Drop the partitions marked with PART_TO_BE_DROPPED state and remove those partitions from the list. Parameters used: table Table object db Database name table_name Table name */ static bool mysql_drop_partitions(ALTER_PARTITION_PARAM_TYPE *lpt) { char path[FN_REFLEN+1]; partition_info *part_info= lpt->table->part_info; List_iterator part_it(part_info->partitions); uint i= 0; uint remove_count= 0; int error; DBUG_ENTER("mysql_drop_partitions"); build_table_filename(path, sizeof(path), lpt->db, lpt->table_name, "", 0); if ((error= lpt->table->file->ha_drop_partitions(path))) { lpt->table->file->print_error(error, MYF(0)); DBUG_RETURN(TRUE); } do { partition_element *part_elem= part_it++; if (part_elem->part_state == PART_IS_DROPPED) { part_it.remove(); remove_count++; } } while (++i < part_info->no_parts); part_info->no_parts-= remove_count; DBUG_RETURN(FALSE); } /* Insert log entry into list SYNOPSIS insert_part_info_log_entry_list() log_entry RETURN VALUES NONE */ static void insert_part_info_log_entry_list(partition_info *part_info, DDL_LOG_MEMORY_ENTRY *log_entry) { log_entry->next_active_log_entry= part_info->first_log_entry; part_info->first_log_entry= log_entry; } /* Release all log entries for this partition info struct SYNOPSIS release_part_info_log_entries() first_log_entry First log entry in list to release RETURN VALUES NONE */ static void release_part_info_log_entries(DDL_LOG_MEMORY_ENTRY *log_entry) { DBUG_ENTER("release_part_info_log_entries"); while (log_entry) { release_ddl_log_memory_entry(log_entry); log_entry= log_entry->next_active_log_entry; } DBUG_VOID_RETURN; } /* Log an delete/rename frm file SYNOPSIS write_log_replace_delete_frm() lpt Struct for parameters next_entry Next reference to use in log record from_path Name to rename from to_path Name to rename to replace_flag TRUE if replace, else delete RETURN VALUES TRUE Error FALSE Success DESCRIPTION Support routine that writes a replace or delete of an frm file into the ddl log. It also inserts an entry that keeps track of used space into the partition info object */ static bool write_log_replace_delete_frm(ALTER_PARTITION_PARAM_TYPE *lpt, uint next_entry, const char *from_path, const char *to_path, bool replace_flag) { DDL_LOG_ENTRY ddl_log_entry; DDL_LOG_MEMORY_ENTRY *log_entry; DBUG_ENTER("write_log_replace_delete_frm"); if (replace_flag) ddl_log_entry.action_type= DDL_LOG_REPLACE_ACTION; else ddl_log_entry.action_type= DDL_LOG_DELETE_ACTION; ddl_log_entry.next_entry= next_entry; ddl_log_entry.handler_name= reg_ext; ddl_log_entry.name= to_path; if (replace_flag) ddl_log_entry.from_name= from_path; if (write_ddl_log_entry(&ddl_log_entry, &log_entry)) { DBUG_RETURN(TRUE); } insert_part_info_log_entry_list(lpt->part_info, log_entry); DBUG_RETURN(FALSE); } /* Log final partition changes in change partition SYNOPSIS write_log_changed_partitions() lpt Struct containing parameters RETURN VALUES TRUE Error FALSE Success DESCRIPTION This code is used to perform safe ADD PARTITION for HASH partitions and COALESCE for HASH partitions and REORGANIZE for any type of partitions. We prepare entries for all partitions except the reorganised partitions in REORGANIZE partition, those are handled by write_log_dropped_partitions. For those partitions that are replaced special care is needed to ensure that this is performed correctly and this requires a two-phased approach with this log as a helper for this. This code is closely intertwined with the code in rename_partitions in the partition handler. */ static bool write_log_changed_partitions(ALTER_PARTITION_PARAM_TYPE *lpt, uint *next_entry, const char *path) { DDL_LOG_ENTRY ddl_log_entry; partition_info *part_info= lpt->part_info; DDL_LOG_MEMORY_ENTRY *log_entry; char tmp_path[FN_REFLEN]; char normal_path[FN_REFLEN]; List_iterator part_it(part_info->partitions); uint temp_partitions= part_info->temp_partitions.elements; uint no_elements= part_info->partitions.elements; uint i= 0; DBUG_ENTER("write_log_changed_partitions"); do { partition_element *part_elem= part_it++; if (part_elem->part_state == PART_IS_CHANGED || (part_elem->part_state == PART_IS_ADDED && temp_partitions)) { if (part_info->is_sub_partitioned()) { List_iterator sub_it(part_elem->subpartitions); uint no_subparts= part_info->no_subparts; uint j= 0; do { partition_element *sub_elem= sub_it++; ddl_log_entry.next_entry= *next_entry; ddl_log_entry.handler_name= ha_resolve_storage_engine_name(sub_elem->engine_type); create_subpartition_name(tmp_path, path, part_elem->partition_name, sub_elem->partition_name, TEMP_PART_NAME); create_subpartition_name(normal_path, path, part_elem->partition_name, sub_elem->partition_name, NORMAL_PART_NAME); ddl_log_entry.name= normal_path; ddl_log_entry.from_name= tmp_path; if (part_elem->part_state == PART_IS_CHANGED) ddl_log_entry.action_type= DDL_LOG_REPLACE_ACTION; else ddl_log_entry.action_type= DDL_LOG_RENAME_ACTION; if (write_ddl_log_entry(&ddl_log_entry, &log_entry)) { DBUG_RETURN(TRUE); } *next_entry= log_entry->entry_pos; sub_elem->log_entry= log_entry; insert_part_info_log_entry_list(part_info, log_entry); } while (++j < no_subparts); } else { ddl_log_entry.next_entry= *next_entry; ddl_log_entry.handler_name= ha_resolve_storage_engine_name(part_elem->engine_type); create_partition_name(tmp_path, path, part_elem->partition_name, TEMP_PART_NAME, TRUE); create_partition_name(normal_path, path, part_elem->partition_name, NORMAL_PART_NAME, TRUE); ddl_log_entry.name= normal_path; ddl_log_entry.from_name= tmp_path; if (part_elem->part_state == PART_IS_CHANGED) ddl_log_entry.action_type= DDL_LOG_REPLACE_ACTION; else ddl_log_entry.action_type= DDL_LOG_RENAME_ACTION; if (write_ddl_log_entry(&ddl_log_entry, &log_entry)) { DBUG_RETURN(TRUE); } *next_entry= log_entry->entry_pos; part_elem->log_entry= log_entry; insert_part_info_log_entry_list(part_info, log_entry); } } } while (++i < no_elements); DBUG_RETURN(FALSE); } /* Log dropped partitions SYNOPSIS write_log_dropped_partitions() lpt Struct containing parameters RETURN VALUES TRUE Error FALSE Success */ static bool write_log_dropped_partitions(ALTER_PARTITION_PARAM_TYPE *lpt, uint *next_entry, const char *path, bool temp_list) { DDL_LOG_ENTRY ddl_log_entry; partition_info *part_info= lpt->part_info; DDL_LOG_MEMORY_ENTRY *log_entry; char tmp_path[FN_LEN]; List_iterator part_it(part_info->partitions); List_iterator temp_it(part_info->temp_partitions); uint no_temp_partitions= part_info->temp_partitions.elements; uint no_elements= part_info->partitions.elements; DBUG_ENTER("write_log_dropped_partitions"); ddl_log_entry.action_type= DDL_LOG_DELETE_ACTION; if (temp_list) no_elements= no_temp_partitions; while (no_elements--) { partition_element *part_elem; if (temp_list) part_elem= temp_it++; else part_elem= part_it++; if (part_elem->part_state == PART_TO_BE_DROPPED || part_elem->part_state == PART_TO_BE_ADDED || part_elem->part_state == PART_CHANGED) { uint name_variant; if (part_elem->part_state == PART_CHANGED || (part_elem->part_state == PART_TO_BE_ADDED && no_temp_partitions)) name_variant= TEMP_PART_NAME; else name_variant= NORMAL_PART_NAME; if (part_info->is_sub_partitioned()) { List_iterator sub_it(part_elem->subpartitions); uint no_subparts= part_info->no_subparts; uint j= 0; do { partition_element *sub_elem= sub_it++; ddl_log_entry.next_entry= *next_entry; ddl_log_entry.handler_name= ha_resolve_storage_engine_name(sub_elem->engine_type); create_subpartition_name(tmp_path, path, part_elem->partition_name, sub_elem->partition_name, name_variant); ddl_log_entry.name= tmp_path; if (write_ddl_log_entry(&ddl_log_entry, &log_entry)) { DBUG_RETURN(TRUE); } *next_entry= log_entry->entry_pos; sub_elem->log_entry= log_entry; insert_part_info_log_entry_list(part_info, log_entry); } while (++j < no_subparts); } else { ddl_log_entry.next_entry= *next_entry; ddl_log_entry.handler_name= ha_resolve_storage_engine_name(part_elem->engine_type); create_partition_name(tmp_path, path, part_elem->partition_name, name_variant, TRUE); ddl_log_entry.name= tmp_path; if (write_ddl_log_entry(&ddl_log_entry, &log_entry)) { DBUG_RETURN(TRUE); } *next_entry= log_entry->entry_pos; part_elem->log_entry= log_entry; insert_part_info_log_entry_list(part_info, log_entry); } } } DBUG_RETURN(FALSE); } /* Set execute log entry in ddl log for this partitioned table SYNOPSIS set_part_info_exec_log_entry() part_info Partition info object exec_log_entry Log entry RETURN VALUES NONE */ static void set_part_info_exec_log_entry(partition_info *part_info, DDL_LOG_MEMORY_ENTRY *exec_log_entry) { part_info->exec_log_entry= exec_log_entry; exec_log_entry->next_active_log_entry= NULL; } /* Write the log entry to ensure that the shadow frm file is removed at crash. SYNOPSIS write_log_drop_shadow_frm() lpt Struct containing parameters install_frm Should we log action to install shadow frm or should the action be to remove the shadow frm file. RETURN VALUES TRUE Error FALSE Success DESCRIPTION Prepare an entry to the ddl log indicating a drop/install of the shadow frm file and its corresponding handler file. */ static bool write_log_drop_shadow_frm(ALTER_PARTITION_PARAM_TYPE *lpt) { partition_info *part_info= lpt->part_info; DDL_LOG_MEMORY_ENTRY *log_entry; DDL_LOG_MEMORY_ENTRY *exec_log_entry= NULL; char shadow_path[FN_REFLEN]; DBUG_ENTER("write_log_drop_shadow_frm"); build_table_shadow_filename(shadow_path, sizeof(shadow_path), lpt); pthread_mutex_lock(&LOCK_gdl); if (write_log_replace_delete_frm(lpt, 0UL, NULL, (const char*)shadow_path, FALSE)) goto error; log_entry= part_info->first_log_entry; if (write_execute_ddl_log_entry(log_entry->entry_pos, FALSE, &exec_log_entry)) goto error; pthread_mutex_unlock(&LOCK_gdl); set_part_info_exec_log_entry(part_info, exec_log_entry); DBUG_RETURN(FALSE); error: release_part_info_log_entries(part_info->first_log_entry); pthread_mutex_unlock(&LOCK_gdl); part_info->first_log_entry= NULL; my_error(ER_DDL_LOG_ERROR, MYF(0)); DBUG_RETURN(TRUE); } /* Log renaming of shadow frm to real frm name and dropping of old frm SYNOPSIS write_log_rename_frm() lpt Struct containing parameters RETURN VALUES TRUE Error FALSE Success DESCRIPTION Prepare an entry to ensure that we complete the renaming of the frm file if failure occurs in the middle of the rename process. */ static bool write_log_rename_frm(ALTER_PARTITION_PARAM_TYPE *lpt) { partition_info *part_info= lpt->part_info; DDL_LOG_MEMORY_ENTRY *log_entry; DDL_LOG_MEMORY_ENTRY *exec_log_entry= part_info->exec_log_entry; char path[FN_REFLEN]; char shadow_path[FN_REFLEN]; DDL_LOG_MEMORY_ENTRY *old_first_log_entry= part_info->first_log_entry; DBUG_ENTER("write_log_rename_frm"); part_info->first_log_entry= NULL; build_table_filename(path, sizeof(path), lpt->db, lpt->table_name, "", 0); build_table_shadow_filename(shadow_path, sizeof(shadow_path), lpt); pthread_mutex_lock(&LOCK_gdl); if (write_log_replace_delete_frm(lpt, 0UL, shadow_path, path, TRUE)) goto error; log_entry= part_info->first_log_entry; part_info->frm_log_entry= log_entry; if (write_execute_ddl_log_entry(log_entry->entry_pos, FALSE, &exec_log_entry)) goto error; release_part_info_log_entries(old_first_log_entry); pthread_mutex_unlock(&LOCK_gdl); DBUG_RETURN(FALSE); error: release_part_info_log_entries(part_info->first_log_entry); pthread_mutex_unlock(&LOCK_gdl); part_info->first_log_entry= old_first_log_entry; part_info->frm_log_entry= NULL; my_error(ER_DDL_LOG_ERROR, MYF(0)); DBUG_RETURN(TRUE); } /* Write the log entries to ensure that the drop partition command is completed even in the presence of a crash. SYNOPSIS write_log_drop_partition() lpt Struct containing parameters RETURN VALUES TRUE Error FALSE Success DESCRIPTION Prepare entries to the ddl log indicating all partitions to drop and to install the shadow frm file and remove the old frm file. */ static bool write_log_drop_partition(ALTER_PARTITION_PARAM_TYPE *lpt) { partition_info *part_info= lpt->part_info; DDL_LOG_MEMORY_ENTRY *log_entry; DDL_LOG_MEMORY_ENTRY *exec_log_entry= part_info->exec_log_entry; char tmp_path[FN_REFLEN]; char path[FN_REFLEN]; uint next_entry= 0; DDL_LOG_MEMORY_ENTRY *old_first_log_entry= part_info->first_log_entry; DBUG_ENTER("write_log_drop_partition"); part_info->first_log_entry= NULL; build_table_filename(path, sizeof(path), lpt->db, lpt->table_name, "", 0); build_table_filename(tmp_path, sizeof(tmp_path), lpt->db, lpt->table_name, "#", 0); pthread_mutex_lock(&LOCK_gdl); if (write_log_dropped_partitions(lpt, &next_entry, (const char*)path, FALSE)) goto error; if (write_log_replace_delete_frm(lpt, next_entry, (const char*)tmp_path, (const char*)path, TRUE)) goto error; log_entry= part_info->first_log_entry; part_info->frm_log_entry= log_entry; if (write_execute_ddl_log_entry(log_entry->entry_pos, FALSE, &exec_log_entry)) goto error; release_part_info_log_entries(old_first_log_entry); pthread_mutex_unlock(&LOCK_gdl); DBUG_RETURN(FALSE); error: release_part_info_log_entries(part_info->first_log_entry); pthread_mutex_unlock(&LOCK_gdl); part_info->first_log_entry= old_first_log_entry; part_info->frm_log_entry= NULL; my_error(ER_DDL_LOG_ERROR, MYF(0)); DBUG_RETURN(TRUE); } /* Write the log entries to ensure that the add partition command is not executed at all if a crash before it has completed SYNOPSIS write_log_add_change_partition() lpt Struct containing parameters RETURN VALUES TRUE Error FALSE Success DESCRIPTION Prepare entries to the ddl log indicating all partitions to drop and to remove the shadow frm file. We always inject entries backwards in the list in the ddl log since we don't know the entry position until we have written it. */ static bool write_log_add_change_partition(ALTER_PARTITION_PARAM_TYPE *lpt) { partition_info *part_info= lpt->part_info; DDL_LOG_MEMORY_ENTRY *log_entry; DDL_LOG_MEMORY_ENTRY *exec_log_entry= NULL; char tmp_path[FN_REFLEN]; char path[FN_REFLEN]; uint next_entry= 0; DBUG_ENTER("write_log_add_change_partition"); build_table_filename(path, sizeof(path), lpt->db, lpt->table_name, "", 0); build_table_filename(tmp_path, sizeof(tmp_path), lpt->db, lpt->table_name, "#", 0); pthread_mutex_lock(&LOCK_gdl); if (write_log_dropped_partitions(lpt, &next_entry, (const char*)path, FALSE)) goto error; if (write_log_replace_delete_frm(lpt, next_entry, NULL, tmp_path, FALSE)) goto error; log_entry= part_info->first_log_entry; if (write_execute_ddl_log_entry(log_entry->entry_pos, FALSE, &exec_log_entry)) goto error; pthread_mutex_unlock(&LOCK_gdl); set_part_info_exec_log_entry(part_info, exec_log_entry); DBUG_RETURN(FALSE); error: release_part_info_log_entries(part_info->first_log_entry); pthread_mutex_unlock(&LOCK_gdl); part_info->first_log_entry= NULL; my_error(ER_DDL_LOG_ERROR, MYF(0)); DBUG_RETURN(TRUE); } /* Write description of how to complete the operation after first phase of change partitions. SYNOPSIS write_log_final_change_partition() lpt Struct containing parameters RETURN VALUES TRUE Error FALSE Success DESCRIPTION We will write log entries that specify to remove all partitions reorganised, to rename others to reflect the new naming scheme and to install the shadow frm file. */ static bool write_log_final_change_partition(ALTER_PARTITION_PARAM_TYPE *lpt) { partition_info *part_info= lpt->part_info; DDL_LOG_MEMORY_ENTRY *log_entry; DDL_LOG_MEMORY_ENTRY *exec_log_entry= part_info->exec_log_entry; char path[FN_REFLEN]; char shadow_path[FN_REFLEN]; DDL_LOG_MEMORY_ENTRY *old_first_log_entry= part_info->first_log_entry; uint next_entry= 0; DBUG_ENTER("write_log_final_change_partition"); part_info->first_log_entry= NULL; build_table_filename(path, sizeof(path), lpt->db, lpt->table_name, "", 0); build_table_shadow_filename(shadow_path, sizeof(shadow_path), lpt); pthread_mutex_lock(&LOCK_gdl); if (write_log_dropped_partitions(lpt, &next_entry, (const char*)path, lpt->alter_info->flags & ALTER_REORGANIZE_PARTITION)) goto error; if (write_log_changed_partitions(lpt, &next_entry, (const char*)path)) goto error; if (write_log_replace_delete_frm(lpt, 0UL, shadow_path, path, TRUE)) goto error; log_entry= part_info->first_log_entry; part_info->frm_log_entry= log_entry; if (write_execute_ddl_log_entry(log_entry->entry_pos, FALSE, &exec_log_entry)) goto error; release_part_info_log_entries(old_first_log_entry); pthread_mutex_unlock(&LOCK_gdl); DBUG_RETURN(FALSE); error: release_part_info_log_entries(part_info->first_log_entry); pthread_mutex_unlock(&LOCK_gdl); part_info->first_log_entry= old_first_log_entry; part_info->frm_log_entry= NULL; my_error(ER_DDL_LOG_ERROR, MYF(0)); DBUG_RETURN(TRUE); } /* Remove entry from ddl log and release resources for others to use SYNOPSIS write_log_completed() lpt Struct containing parameters RETURN VALUES TRUE Error FALSE Success */ static void write_log_completed(ALTER_PARTITION_PARAM_TYPE *lpt, bool dont_crash) { partition_info *part_info= lpt->part_info; DDL_LOG_MEMORY_ENTRY *log_entry= part_info->exec_log_entry; DBUG_ENTER("write_log_completed"); DBUG_ASSERT(log_entry); pthread_mutex_lock(&LOCK_gdl); if (write_execute_ddl_log_entry(0UL, TRUE, &log_entry)) { /* Failed to write, Bad... We have completed the operation but have log records to REMOVE stuff that shouldn't be removed. What clever things could one do here? An error output was written to the error output by the above method so we don't do anything here. */ ; } release_part_info_log_entries(part_info->first_log_entry); release_part_info_log_entries(part_info->exec_log_entry); pthread_mutex_unlock(&LOCK_gdl); part_info->exec_log_entry= NULL; part_info->first_log_entry= NULL; DBUG_VOID_RETURN; } /* Release all log entries SYNOPSIS release_log_entries() part_info Partition info struct RETURN VALUES NONE */ static void release_log_entries(partition_info *part_info) { pthread_mutex_lock(&LOCK_gdl); release_part_info_log_entries(part_info->first_log_entry); release_part_info_log_entries(part_info->exec_log_entry); pthread_mutex_unlock(&LOCK_gdl); part_info->first_log_entry= NULL; part_info->exec_log_entry= NULL; } /* Final part of partition changes to handle things when under LOCK TABLES. SYNPOSIS alter_partition_lock_handling() lpt Struct carrying parameters RETURN VALUES NONE */ static void alter_partition_lock_handling(ALTER_PARTITION_PARAM_TYPE *lpt) { int err; if (lpt->thd->locked_tables) { /* When we have the table locked, it is necessary to reopen the table since all table objects were closed and removed as part of the ALTER TABLE of partitioning structure. */ pthread_mutex_lock(&LOCK_open); lpt->thd->in_lock_tables= 1; err= reopen_tables(lpt->thd, 1, 1); lpt->thd->in_lock_tables= 0; if (err) { /* Issue a warning since we weren't able to regain the lock again. We also need to unlink table from thread's open list and from table_cache */ unlink_open_table(lpt->thd, lpt->table, FALSE); sql_print_warning("We failed to reacquire LOCKs in ALTER TABLE"); } pthread_mutex_unlock(&LOCK_open); } } /* Unlock and close table before renaming and dropping partitions SYNOPSIS alter_close_tables() lpt Struct carrying parameters RETURN VALUES 0 */ static int alter_close_tables(ALTER_PARTITION_PARAM_TYPE *lpt) { THD *thd= lpt->thd; const char *db= lpt->db; const char *table_name= lpt->table_name; DBUG_ENTER("alter_close_tables"); /* We need to also unlock tables and close all handlers. We set lock to zero to ensure we don't do this twice and we set db_stat to zero to ensure we don't close twice. */ pthread_mutex_lock(&LOCK_open); close_data_files_and_morph_locks(thd, db, table_name); pthread_mutex_unlock(&LOCK_open); DBUG_RETURN(0); } /* Handle errors for ALTER TABLE for partitioning SYNOPSIS handle_alter_part_error() lpt Struct carrying parameters not_completed Was request in complete phase when error occurred RETURN VALUES NONE */ void handle_alter_part_error(ALTER_PARTITION_PARAM_TYPE *lpt, bool not_completed, bool drop_partition, bool frm_install) { partition_info *part_info= lpt->part_info; DBUG_ENTER("handle_alter_part_error"); if (!part_info->first_log_entry && execute_ddl_log_entry(current_thd, part_info->first_log_entry->entry_pos)) { /* We couldn't recover from error, most likely manual interaction is required. */ write_log_completed(lpt, FALSE); release_log_entries(part_info); if (not_completed) { if (drop_partition) { /* Table is still ok, but we left a shadow frm file behind. */ push_warning_printf(lpt->thd, MYSQL_ERROR::WARN_LEVEL_WARN, 1, "%s %s", "Operation was unsuccessful, table is still intact,", "but it is possible that a shadow frm file was left behind"); } else { push_warning_printf(lpt->thd, MYSQL_ERROR::WARN_LEVEL_WARN, 1, "%s %s %s %s", "Operation was unsuccessful, table is still intact,", "but it is possible that a shadow frm file was left behind.", "It is also possible that temporary partitions are left behind,", "these could be empty or more or less filled with records"); } } else { if (frm_install) { /* Failed during install of shadow frm file, table isn't intact and dropped partitions are still there */ push_warning_printf(lpt->thd, MYSQL_ERROR::WARN_LEVEL_WARN, 1, "%s %s %s", "Failed during alter of partitions, table is no longer intact.", "The frm file is in an unknown state, and a backup", "is required."); } else if (drop_partition) { /* Table is ok, we have switched to new table but left dropped partitions still in their places. We remove the log records and ask the user to perform the action manually. We remove the log records and ask the user to perform the action manually. */ push_warning_printf(lpt->thd, MYSQL_ERROR::WARN_LEVEL_WARN, 1, "%s %s", "Failed during drop of partitions, table is intact.", "Manual drop of remaining partitions is required"); } else { /* We failed during renaming of partitions. The table is most certainly in a very bad state so we give user warning and disable the table by writing an ancient frm version into it. */ push_warning_printf(lpt->thd, MYSQL_ERROR::WARN_LEVEL_WARN, 1, "%s %s %s", "Failed during renaming of partitions. We are now in a position", "where table is not reusable", "Table is disabled by writing ancient frm file version into it"); } } } else { release_log_entries(part_info); if (not_completed) { /* We hit an error before things were completed but managed to recover from the error. An error occurred and we have restored things to original so no need for further action. */ ; } else { /* We hit an error after we had completed most of the operation and were successful in a second attempt so the operation actually is successful now. We need to issue a warning that even though we reported an error the operation was successfully completed. */ push_warning_printf(lpt->thd, MYSQL_ERROR::WARN_LEVEL_WARN, 1,"%s %s", "Operation was successfully completed by failure handling,", "after failure of normal operation"); } } DBUG_VOID_RETURN; } /* Actually perform the change requested by ALTER TABLE of partitions previously prepared. SYNOPSIS fast_alter_partition_table() thd Thread object table Table object alter_info ALTER TABLE info create_info Create info for CREATE TABLE table_list List of the table involved db Database name of new table table_name Table name of new table RETURN VALUES TRUE Error FALSE Success DESCRIPTION Perform all ALTER TABLE operations for partitioned tables that can be performed fast without a full copy of the original table. */ uint fast_alter_partition_table(THD *thd, TABLE *table, Alter_info *alter_info, HA_CREATE_INFO *create_info, TABLE_LIST *table_list, char *db, const char *table_name, uint fast_alter_partition) { /* Set-up struct used to write frm files */ partition_info *part_info= table->part_info; ALTER_PARTITION_PARAM_TYPE lpt_obj; ALTER_PARTITION_PARAM_TYPE *lpt= &lpt_obj; bool written_bin_log= TRUE; bool not_completed= TRUE; bool frm_install= FALSE; DBUG_ENTER("fast_alter_partition_table"); lpt->thd= thd; lpt->part_info= part_info; lpt->alter_info= alter_info; lpt->create_info= create_info; lpt->db_options= create_info->table_options; if (create_info->row_type == ROW_TYPE_DYNAMIC) lpt->db_options|= HA_OPTION_PACK_RECORD; lpt->table= table; lpt->key_info_buffer= 0; lpt->key_count= 0; lpt->db= db; lpt->table_name= table_name; lpt->copied= 0; lpt->deleted= 0; lpt->pack_frm_data= NULL; lpt->pack_frm_len= 0; thd->work_part_info= part_info; if (fast_alter_partition & HA_PARTITION_ONE_PHASE) { /* In the case where the engine supports one phase online partition changes it is not necessary to have any exclusive locks. The correctness is upheld instead by transactions being aborted if they access the table after its partition definition has changed (if they are still using the old partition definition). The handler is in this case responsible to ensure that all users start using the new frm file after it has changed. To implement one phase it is necessary for the handler to have the master copy of the frm file and use discovery mechanisms to renew it. Thus write frm will write the frm, pack the new frm and finally the frm is deleted and the discovery mechanisms will either restore back to the old or installing the new after the change is activated. Thus all open tables will be discovered that they are old, if not earlier as soon as they try an operation using the old table. One should ensure that this is checked already when opening a table, even if it is found in the cache of open tables. change_partitions will perform all operations and it is the duty of the handler to ensure that the frm files in the system gets updated in synch with the changes made and if an error occurs that a proper error handling is done. If the MySQL Server crashes at this moment but the handler succeeds in performing the change then the binlog is not written for the change. There is no way to solve this as long as the binlog is not transactional and even then it is hard to solve it completely. The first approach here was to downgrade locks. Now a different approach is decided upon. The idea is that the handler will have access to the Alter_info when store_lock arrives with TL_WRITE_ALLOW_READ. So if the handler knows that this functionality can be handled with a lower lock level it will set the lock level to TL_WRITE_ALLOW_WRITE immediately. Thus the need to downgrade the lock disappears. 1) Write the new frm, pack it and then delete it 2) Perform the change within the handler */ if (mysql_write_frm(lpt, WFRM_WRITE_SHADOW | WFRM_PACK_FRM) || mysql_change_partitions(lpt)) { goto err; } } else if (alter_info->flags & ALTER_DROP_PARTITION) { /* Now after all checks and setting state on dropped partitions we can start the actual dropping of the partitions. Drop partition is actually two things happening. The first is that a lot of records are deleted. The second is that the behaviour of subsequent updates and writes and deletes will change. The delete part can be handled without any particular high lock level by transactional engines whereas non-transactional engines need to ensure that this change is done with an exclusive lock on the table. The second part, the change of partitioning does however require an exclusive lock to install the new partitioning as one atomic operation. If this is not the case, it is possible for two transactions to see the change in a different order than their serialisation order. Thus we need an exclusive lock for both transactional and non-transactional engines. For LIST partitions it could be possible to avoid the exclusive lock (and for RANGE partitions if they didn't rearrange range definitions after a DROP PARTITION) if one ensured that failed accesses to the dropped partitions was aborted for sure (thus only possible for transactional engines). 0) Write an entry that removes the shadow frm file if crash occurs 1) Write the new frm file as a shadow frm 2) Write the ddl log to ensure that the operation is completed even in the presence of a MySQL Server crash 3) Lock the table in TL_WRITE_ONLY to ensure all other accesses to the table have completed. This ensures that other threads can not execute on the table in parallel. 4) Get a name lock on the table. This ensures that we can release all locks on the table and since no one can open the table, there can be no new threads accessing the table. They will be hanging on the name lock. 5) Close all tables that have already been opened but didn't stumble on the abort locked previously. This is done as part of the close_data_files_and_morph_locks call. 6) We are now ready to release all locks we got in this thread. 7) Write the bin log Unfortunately the writing of the binlog is not synchronised with other logging activities. So no matter in which order the binlog is written compared to other activities there will always be cases where crashes make strange things occur. In this placement it can happen that the ALTER TABLE DROP PARTITION gets performed in the master but not in the slaves if we have a crash, after writing the ddl log but before writing the binlog. A solution to this would require writing the statement first in the ddl log and then when recovering from the crash read the binlog and insert it into the binlog if not written already. 8) Install the previously written shadow frm file 9) Prepare handlers for drop of partitions 10) Drop the partitions 11) Remove entries from ddl log 12) Reopen table if under lock tables 13) Complete query We insert Error injections at all places where it could be interesting to test if recovery is properly done. */ if (write_log_drop_shadow_frm(lpt) || ERROR_INJECT_CRASH("crash_drop_partition_1") || mysql_write_frm(lpt, WFRM_WRITE_SHADOW) || ERROR_INJECT_CRASH("crash_drop_partition_2") || write_log_drop_partition(lpt) || ERROR_INJECT_CRASH("crash_drop_partition_3") || (not_completed= FALSE) || abort_and_upgrade_lock(lpt) || /* Always returns 0 */ ERROR_INJECT_CRASH("crash_drop_partition_4") || alter_close_tables(lpt) || ERROR_INJECT_CRASH("crash_drop_partition_5") || ((!thd->lex->no_write_to_binlog) && (write_bin_log(thd, FALSE, thd->query, thd->query_length), FALSE)) || ERROR_INJECT_CRASH("crash_drop_partition_6") || ((frm_install= TRUE), FALSE) || mysql_write_frm(lpt, WFRM_INSTALL_SHADOW) || ((frm_install= FALSE), FALSE) || ERROR_INJECT_CRASH("crash_drop_partition_7") || mysql_drop_partitions(lpt) || ERROR_INJECT_CRASH("crash_drop_partition_8") || (write_log_completed(lpt, FALSE), FALSE) || ERROR_INJECT_CRASH("crash_drop_partition_9") || (alter_partition_lock_handling(lpt), FALSE)) { handle_alter_part_error(lpt, not_completed, TRUE, frm_install); goto err; } } else if ((alter_info->flags & ALTER_ADD_PARTITION) && (part_info->part_type == RANGE_PARTITION || part_info->part_type == LIST_PARTITION)) { /* ADD RANGE/LIST PARTITIONS In this case there are no tuples removed and no tuples are added. Thus the operation is merely adding a new partition. Thus it is necessary to perform the change as an atomic operation. Otherwise someone reading without seeing the new partition could potentially miss updates made by a transaction serialised before it that are inserted into the new partition. 0) Write an entry that removes the shadow frm file if crash occurs 1) Write the new frm file as a shadow frm file 2) Log the changes to happen in ddl log 2) Add the new partitions 3) Lock all partitions in TL_WRITE_ONLY to ensure that no users are still using the old partitioning scheme. Wait until all ongoing users have completed before progressing. 4) Get a name lock on the table. This ensures that we can release all locks on the table and since no one can open the table, there can be no new threads accessing the table. They will be hanging on the name lock. 5) Close all tables that have already been opened but didn't stumble on the abort locked previously. This is done as part of the close_data_files_and_morph_locks call. 6) Close all table handlers and unlock all handlers but retain name lock 7) Write binlog 8) Now the change is completed except for the installation of the new frm file. We thus write an action in the log to change to the shadow frm file 9) Install the new frm file of the table where the partitions are added to the table. 10)Wait until all accesses using the old frm file has completed 11)Remove entries from ddl log 12)Reopen tables if under lock tables 13)Complete query */ if (write_log_add_change_partition(lpt) || ERROR_INJECT_CRASH("crash_add_partition_1") || mysql_write_frm(lpt, WFRM_WRITE_SHADOW) || ERROR_INJECT_CRASH("crash_add_partition_2") || mysql_change_partitions(lpt) || ERROR_INJECT_CRASH("crash_add_partition_3") || abort_and_upgrade_lock(lpt) || /* Always returns 0 */ ERROR_INJECT_CRASH("crash_add_partition_4") || alter_close_tables(lpt) || ERROR_INJECT_CRASH("crash_add_partition_5") || ((!thd->lex->no_write_to_binlog) && (write_bin_log(thd, FALSE, thd->query, thd->query_length), FALSE)) || ERROR_INJECT_CRASH("crash_add_partition_6") || write_log_rename_frm(lpt) || (not_completed= FALSE) || ERROR_INJECT_CRASH("crash_add_partition_7") || ((frm_install= TRUE), FALSE) || mysql_write_frm(lpt, WFRM_INSTALL_SHADOW) || ERROR_INJECT_CRASH("crash_add_partition_8") || (write_log_completed(lpt, FALSE), FALSE) || ERROR_INJECT_CRASH("crash_add_partition_9") || (alter_partition_lock_handling(lpt), FALSE)) { handle_alter_part_error(lpt, not_completed, FALSE, frm_install); goto err; } } else { /* ADD HASH PARTITION/ COALESCE PARTITION/ REBUILD PARTITION/ REORGANIZE PARTITION In this case all records are still around after the change although possibly organised into new partitions, thus by ensuring that all updates go to both the old and the new partitioning scheme we can actually perform this operation lock-free. The only exception to this is when REORGANIZE PARTITION adds/drops ranges. In this case there needs to be an exclusive lock during the time when the range changes occur. This is only possible if the handler can ensure double-write for a period. The double write will ensure that it doesn't matter where the data is read from since both places are updated for writes. If such double writing is not performed then it is necessary to perform the change with the usual exclusive lock. With double writes it is even possible to perform writes in parallel with the reorganisation of partitions. Without double write procedure we get the following procedure. The only difference with using double write is that we can downgrade the lock to TL_WRITE_ALLOW_WRITE. Double write in this case only double writes from old to new. If we had double writing in both directions we could perform the change completely without exclusive lock for HASH partitions. Handlers that perform double writing during the copy phase can actually use a lower lock level. This can be handled inside store_lock in the respective handler. 0) Write an entry that removes the shadow frm file if crash occurs 1) Write the shadow frm file of new partitioning 2) Log such that temporary partitions added in change phase are removed in a crash situation 3) Add the new partitions Copy from the reorganised partitions to the new partitions 4) Log that operation is completed and log all complete actions needed to complete operation from here 5) Lock all partitions in TL_WRITE_ONLY to ensure that no users are still using the old partitioning scheme. Wait until all ongoing users have completed before progressing. 6) Get a name lock of the table 7) Close all tables opened but not yet locked, after this call we are certain that no other thread is in the lock wait queue or has opened the table. The name lock will ensure that they are blocked on the open call. This is achieved also by close_data_files_and_morph_locks call. 8) Close all partitions opened by this thread, but retain name lock. 9) Write bin log 10) Prepare handlers for rename and delete of partitions 11) Rename and drop the reorged partitions such that they are no longer used and rename those added to their real new names. 12) Install the shadow frm file 13) Reopen the table if under lock tables 14) Complete query */ if (write_log_add_change_partition(lpt) || ERROR_INJECT_CRASH("crash_change_partition_1") || mysql_write_frm(lpt, WFRM_WRITE_SHADOW) || ERROR_INJECT_CRASH("crash_change_partition_2") || mysql_change_partitions(lpt) || ERROR_INJECT_CRASH("crash_change_partition_3") || write_log_final_change_partition(lpt) || ERROR_INJECT_CRASH("crash_change_partition_4") || (not_completed= FALSE) || abort_and_upgrade_lock(lpt) || /* Always returns 0 */ ERROR_INJECT_CRASH("crash_change_partition_5") || alter_close_tables(lpt) || ERROR_INJECT_CRASH("crash_change_partition_6") || ((!thd->lex->no_write_to_binlog) && (write_bin_log(thd, FALSE, thd->query, thd->query_length), FALSE)) || ERROR_INJECT_CRASH("crash_change_partition_7") || mysql_write_frm(lpt, WFRM_INSTALL_SHADOW) || ERROR_INJECT_CRASH("crash_change_partition_8") || mysql_drop_partitions(lpt) || ERROR_INJECT_CRASH("crash_change_partition_9") || mysql_rename_partitions(lpt) || ((frm_install= TRUE), FALSE) || ERROR_INJECT_CRASH("crash_change_partition_10") || (write_log_completed(lpt, FALSE), FALSE) || ERROR_INJECT_CRASH("crash_change_partition_11") || (alter_partition_lock_handling(lpt), FALSE)) { handle_alter_part_error(lpt, not_completed, FALSE, frm_install); goto err; } } /* A final step is to write the query to the binlog and send ok to the user */ DBUG_RETURN(fast_end_partition(thd, lpt->copied, lpt->deleted, table, table_list, FALSE, NULL, written_bin_log)); err: close_thread_tables(thd); DBUG_RETURN(TRUE); } #endif /* Prepare for calling val_int on partition function by setting fields to point to the record where the values of the PF-fields are stored. SYNOPSIS set_field_ptr() ptr Array of fields to change ptr new_buf New record pointer old_buf Old record pointer DESCRIPTION Set ptr in field objects of field array to refer to new_buf record instead of previously old_buf. Used before calling val_int and after it is used to restore pointers to table->record[0]. This routine is placed outside of partition code since it can be useful also for other programs. */ void set_field_ptr(Field **ptr, const uchar *new_buf, const uchar *old_buf) { my_ptrdiff_t diff= (new_buf - old_buf); DBUG_ENTER("set_field_ptr"); do { (*ptr)->move_field_offset(diff); } while (*(++ptr)); DBUG_VOID_RETURN; } /* Prepare for calling val_int on partition function by setting fields to point to the record where the values of the PF-fields are stored. This variant works on a key_part reference. It is not required that all fields are NOT NULL fields. SYNOPSIS set_key_field_ptr() key_info key info with a set of fields to change ptr new_buf New record pointer old_buf Old record pointer DESCRIPTION Set ptr in field objects of field array to refer to new_buf record instead of previously old_buf. Used before calling val_int and after it is used to restore pointers to table->record[0]. This routine is placed outside of partition code since it can be useful also for other programs. */ void set_key_field_ptr(KEY *key_info, const uchar *new_buf, const uchar *old_buf) { KEY_PART_INFO *key_part= key_info->key_part; uint key_parts= key_info->key_parts; uint i= 0; my_ptrdiff_t diff= (new_buf - old_buf); DBUG_ENTER("set_key_field_ptr"); do { key_part->field->move_field_offset(diff); key_part++; } while (++i < key_parts); DBUG_VOID_RETURN; } /* SYNOPSIS mem_alloc_error() size Size of memory attempted to allocate None RETURN VALUES None DESCRIPTION A routine to use for all the many places in the code where memory allocation error can happen, a tremendous amount of them, needs simple routine that signals this error. */ void mem_alloc_error(size_t size) { my_error(ER_OUTOFMEMORY, MYF(0), size); } #ifdef WITH_PARTITION_STORAGE_ENGINE /* Return comma-separated list of used partitions in the provided given string SYNOPSIS make_used_partitions_str() part_info IN Partitioning info parts_str OUT The string to fill DESCRIPTION Generate a list of used partitions (from bits in part_info->used_partitions bitmap), asd store it into the provided String object. NOTE The produced string must not be longer then MAX_PARTITIONS * (1 + FN_LEN). */ void make_used_partitions_str(partition_info *part_info, String *parts_str) { parts_str->length(0); partition_element *pe; uint partition_id= 0; List_iterator it(part_info->partitions); if (part_info->is_sub_partitioned()) { partition_element *head_pe; while ((head_pe= it++)) { List_iterator it2(head_pe->subpartitions); while ((pe= it2++)) { if (bitmap_is_set(&part_info->used_partitions, partition_id)) { if (parts_str->length()) parts_str->append(','); parts_str->append(head_pe->partition_name, strlen(head_pe->partition_name), system_charset_info); parts_str->append('_'); parts_str->append(pe->partition_name, strlen(pe->partition_name), system_charset_info); } partition_id++; } } } else { while ((pe= it++)) { if (bitmap_is_set(&part_info->used_partitions, partition_id)) { if (parts_str->length()) parts_str->append(','); parts_str->append(pe->partition_name, strlen(pe->partition_name), system_charset_info); } partition_id++; } } } #endif /**************************************************************************** * Partition interval analysis support ***************************************************************************/ /* Setup partition_info::* members related to partitioning range analysis SYNOPSIS set_up_partition_func_pointers() part_info Partitioning info structure DESCRIPTION Assuming that passed partition_info structure already has correct values for members that specify [sub]partitioning type, table fields, and functions, set up partition_info::* members that are related to Partitioning Interval Analysis (see get_partitions_in_range_iter for its definition) IMPLEMENTATION There are two available interval analyzer functions: (1) get_part_iter_for_interval_via_mapping (2) get_part_iter_for_interval_via_walking They both have limited applicability: (1) is applicable for "PARTITION BY (func(t.field))", where func is a monotonic function. (2) is applicable for "[SUB]PARTITION BY (any_func(t.integer_field))" If both are applicable, (1) is preferred over (2). This function sets part_info::get_part_iter_for_interval according to this criteria, and also sets some auxilary fields that the function uses. */ #ifdef WITH_PARTITION_STORAGE_ENGINE static void set_up_range_analysis_info(partition_info *part_info) { /* Set the catch-all default */ part_info->get_part_iter_for_interval= NULL; part_info->get_subpart_iter_for_interval= NULL; /* Check if get_part_iter_for_interval_via_mapping() can be used for partitioning */ switch (part_info->part_type) { case RANGE_PARTITION: case LIST_PARTITION: if (part_info->part_expr->get_monotonicity_info() != NON_MONOTONIC) { part_info->get_part_iter_for_interval= get_part_iter_for_interval_via_mapping; goto setup_subparts; } default: ; } /* Check if get_part_iter_for_interval_via_walking() can be used for partitioning */ if (part_info->no_part_fields == 1) { Field *field= part_info->part_field_array[0]; switch (field->type()) { case MYSQL_TYPE_TINY: case MYSQL_TYPE_SHORT: case MYSQL_TYPE_INT24: case MYSQL_TYPE_LONG: case MYSQL_TYPE_LONGLONG: part_info->get_part_iter_for_interval= get_part_iter_for_interval_via_walking; break; default: ; } } setup_subparts: /* Check if get_part_iter_for_interval_via_walking() can be used for subpartitioning */ if (part_info->no_subpart_fields == 1) { Field *field= part_info->subpart_field_array[0]; switch (field->type()) { case MYSQL_TYPE_TINY: case MYSQL_TYPE_SHORT: case MYSQL_TYPE_LONG: case MYSQL_TYPE_LONGLONG: part_info->get_subpart_iter_for_interval= get_part_iter_for_interval_via_walking; break; default: ; } } } typedef uint32 (*get_endpoint_func)(partition_info*, bool left_endpoint, bool include_endpoint); /* Partitioning Interval Analysis: Initialize the iterator for "mapping" case SYNOPSIS get_part_iter_for_interval_via_mapping() part_info Partition info is_subpart TRUE - act for subpartitioning FALSE - act for partitioning min_value minimum field value, in opt_range key format. max_value minimum field value, in opt_range key format. flags Some combination of NEAR_MIN, NEAR_MAX, NO_MIN_RANGE, NO_MAX_RANGE. part_iter Iterator structure to be initialized DESCRIPTION Initialize partition set iterator to walk over the interval in ordered-array-of-partitions (for RANGE partitioning) or ordered-array-of-list-constants (for LIST partitioning) space. IMPLEMENTATION This function is used when partitioning is done by (ascending_func(t.field)), and we can map an interval in t.field space into a sub-array of partition_info::range_int_array or partition_info::list_array (see get_partition_id_range_for_endpoint, get_list_array_idx_for_endpoint for details). The function performs this interval mapping, and sets the iterator to traverse the sub-array and return appropriate partitions. RETURN 0 - No matching partitions (iterator not initialized) 1 - Ok, iterator intialized for traversal of matching partitions. -1 - All partitions would match (iterator not initialized) */ int get_part_iter_for_interval_via_mapping(partition_info *part_info, bool is_subpart, uchar *min_value, uchar *max_value, uint flags, PARTITION_ITERATOR *part_iter) { DBUG_ASSERT(!is_subpart); Field *field= part_info->part_field_array[0]; uint32 max_endpoint_val; get_endpoint_func get_endpoint; uint field_len= field->pack_length_in_rec(); part_iter->ret_null_part= part_iter->ret_null_part_orig= FALSE; if (part_info->part_type == RANGE_PARTITION) { if (part_info->part_charset_field_array) get_endpoint= get_partition_id_range_for_endpoint_charset; else get_endpoint= get_partition_id_range_for_endpoint; max_endpoint_val= part_info->no_parts; part_iter->get_next= get_next_partition_id_range; } else if (part_info->part_type == LIST_PARTITION) { if (part_info->part_charset_field_array) get_endpoint= get_list_array_idx_for_endpoint_charset; else get_endpoint= get_list_array_idx_for_endpoint; max_endpoint_val= part_info->no_list_values; part_iter->get_next= get_next_partition_id_list; part_iter->part_info= part_info; if (max_endpoint_val == 0) { /* We handle this special case without optimisations since it is of little practical value but causes a great number of complex checks later in the code. */ part_iter->part_nums.start= part_iter->part_nums.end= 0; part_iter->part_nums.cur= 0; part_iter->ret_null_part= part_iter->ret_null_part_orig= TRUE; return -1; } } else assert(0); /* Find minimum: Do special handling if the interval has left bound in form " NULL <= X ": */ if (field->real_maybe_null() && part_info->has_null_value && !(flags & (NO_MIN_RANGE | NEAR_MIN)) && *min_value) { part_iter->ret_null_part= part_iter->ret_null_part_orig= TRUE; part_iter->part_nums.start= part_iter->part_nums.cur= 0; if (*max_value && !(flags & NO_MAX_RANGE)) { /* The right bound is X <= NULL, i.e. it is a "X IS NULL" interval */ part_iter->part_nums.end= 0; return 1; } } else { if (flags & NO_MIN_RANGE) part_iter->part_nums.start= part_iter->part_nums.cur= 0; else { /* Store the interval edge in the record buffer, and call the function that maps the edge in table-field space to an edge in ordered-set-of-partitions (for RANGE partitioning) or index-in-ordered-array-of-list-constants (for LIST) space. */ store_key_image_to_rec(field, min_value, field_len); bool include_endp= !test(flags & NEAR_MIN); part_iter->part_nums.start= get_endpoint(part_info, 1, include_endp); part_iter->part_nums.cur= part_iter->part_nums.start; if (part_iter->part_nums.start == max_endpoint_val) return 0; /* No partitions */ } } /* Find maximum, do the same as above but for right interval bound */ if (flags & NO_MAX_RANGE) part_iter->part_nums.end= max_endpoint_val; else { store_key_image_to_rec(field, max_value, field_len); bool include_endp= !test(flags & NEAR_MAX); part_iter->part_nums.end= get_endpoint(part_info, 0, include_endp); if (part_iter->part_nums.start >= part_iter->part_nums.end && !part_iter->ret_null_part) return 0; /* No partitions */ } return 1; /* Ok, iterator initialized */ } /* See get_part_iter_for_interval_via_walking for definition of what this is */ #define MAX_RANGE_TO_WALK 10 /* Partitioning Interval Analysis: Initialize iterator to walk field interval SYNOPSIS get_part_iter_for_interval_via_walking() part_info Partition info is_subpart TRUE - act for subpartitioning FALSE - act for partitioning min_value minimum field value, in opt_range key format. max_value minimum field value, in opt_range key format. flags Some combination of NEAR_MIN, NEAR_MAX, NO_MIN_RANGE, NO_MAX_RANGE. part_iter Iterator structure to be initialized DESCRIPTION Initialize partition set iterator to walk over interval in integer field space. That is, for "const1 <=? t.field <=? const2" interval, initialize the iterator to return a set of [sub]partitions obtained with the following procedure: get partition id for t.field = const1, return it get partition id for t.field = const1+1, return it ... t.field = const1+2, ... ... ... ... ... t.field = const2 ... IMPLEMENTATION See get_partitions_in_range_iter for general description of interval analysis. We support walking over the following intervals: "t.field IS NULL" "c1 <=? t.field <=? c2", where c1 and c2 are finite. Intervals with +inf/-inf, and [NULL, c1] interval can be processed but that is more tricky and I don't have time to do it right now. Additionally we have these requirements: * number of values in the interval must be less then number of [sub]partitions, and * Number of values in the interval must be less then MAX_RANGE_TO_WALK. The rationale behind these requirements is that if they are not met we're likely to hit most of the partitions and traversing the interval will only add overhead. So it's better return "all partitions used" in that case. RETURN 0 - No matching partitions, iterator not initialized 1 - Some partitions would match, iterator intialized for traversing them -1 - All partitions would match, iterator not initialized */ int get_part_iter_for_interval_via_walking(partition_info *part_info, bool is_subpart, uchar *min_value, uchar *max_value, uint flags, PARTITION_ITERATOR *part_iter) { Field *field; uint total_parts; partition_iter_func get_next_func; if (is_subpart) { field= part_info->subpart_field_array[0]; total_parts= part_info->no_subparts; get_next_func= get_next_subpartition_via_walking; } else { field= part_info->part_field_array[0]; total_parts= part_info->no_parts; get_next_func= get_next_partition_via_walking; } /* Handle the "t.field IS NULL" interval, it is a special case */ if (field->real_maybe_null() && !(flags & (NO_MIN_RANGE | NO_MAX_RANGE)) && *min_value && *max_value) { /* We don't have a part_iter->get_next() function that would find which partition "t.field IS NULL" belongs to, so find partition that contains NULL right here, and return an iterator over singleton set. */ uint32 part_id; field->set_null(); if (is_subpart) { if (!part_info->get_subpartition_id(part_info, &part_id)) { init_single_partition_iterator(part_id, part_iter); return 1; /* Ok, iterator initialized */ } } else { longlong dummy; int res= part_info->is_sub_partitioned() ? part_info->get_part_partition_id(part_info, &part_id, &dummy): part_info->get_partition_id(part_info, &part_id, &dummy); if (!res) { init_single_partition_iterator(part_id, part_iter); return 1; /* Ok, iterator initialized */ } } return 0; /* No partitions match */ } if ((field->real_maybe_null() && ((!(flags & NO_MIN_RANGE) && *min_value) || // NULL pack_length_in_rec(); store_key_image_to_rec(field, min_value, len); a= field->val_int(); store_key_image_to_rec(field, max_value, len); b= field->val_int(); /* Handle a special case where the distance between interval bounds is exactly 4G-1. This interval is too big for range walking, and if it is an (x,y]-type interval then the following "b +=..." code will convert it to an empty interval by "wrapping around" a + 4G-1 + 1 = a. */ if ((ulonglong)b - (ulonglong)a == ~0ULL) return -1; a += test(flags & NEAR_MIN); b += test(!(flags & NEAR_MAX)); ulonglong n_values= b - a; if (n_values > total_parts || n_values > MAX_RANGE_TO_WALK) return -1; part_iter->field_vals.start= part_iter->field_vals.cur= a; part_iter->field_vals.end= b; part_iter->part_info= part_info; part_iter->get_next= get_next_func; return 1; } /* PARTITION_ITERATOR::get_next implementation: enumerate partitions in range SYNOPSIS get_next_partition_id_range() part_iter Partition set iterator structure DESCRIPTION This is implementation of PARTITION_ITERATOR::get_next() that returns [sub]partition ids in [min_partition_id, max_partition_id] range. The function conforms to partition_iter_func type. RETURN partition id NOT_A_PARTITION_ID if there are no more partitions */ uint32 get_next_partition_id_range(PARTITION_ITERATOR* part_iter) { if (part_iter->part_nums.cur >= part_iter->part_nums.end) { part_iter->part_nums.cur= part_iter->part_nums.start; return NOT_A_PARTITION_ID; } else return part_iter->part_nums.cur++; } /* PARTITION_ITERATOR::get_next implementation for LIST partitioning SYNOPSIS get_next_partition_id_list() part_iter Partition set iterator structure DESCRIPTION This implementation of PARTITION_ITERATOR::get_next() is special for LIST partitioning: it enumerates partition ids in part_info->list_array[i] where i runs over [min_idx, max_idx] interval. The function conforms to partition_iter_func type. RETURN partition id NOT_A_PARTITION_ID if there are no more partitions */ uint32 get_next_partition_id_list(PARTITION_ITERATOR *part_iter) { if (part_iter->part_nums.cur == part_iter->part_nums.end) { if (part_iter->ret_null_part) { part_iter->ret_null_part= FALSE; return part_iter->part_info->has_null_part_id; } part_iter->part_nums.cur= part_iter->part_nums.start; part_iter->ret_null_part= part_iter->ret_null_part_orig; return NOT_A_PARTITION_ID; } else return part_iter->part_info->list_array[part_iter-> part_nums.cur++].partition_id; } /* PARTITION_ITERATOR::get_next implementation: walk over field-space interval SYNOPSIS get_next_partition_via_walking() part_iter Partitioning iterator DESCRIPTION This implementation of PARTITION_ITERATOR::get_next() returns ids of partitions that contain records with partitioning field value within [start_val, end_val] interval. The function conforms to partition_iter_func type. RETURN partition id NOT_A_PARTITION_ID if there are no more partitioning. */ static uint32 get_next_partition_via_walking(PARTITION_ITERATOR *part_iter) { uint32 part_id; Field *field= part_iter->part_info->part_field_array[0]; while (part_iter->field_vals.cur != part_iter->field_vals.end) { longlong dummy; field->store(part_iter->field_vals.cur++, ((Field_num*)field)->unsigned_flag); if (part_iter->part_info->is_sub_partitioned() && !part_iter->part_info->get_part_partition_id(part_iter->part_info, &part_id, &dummy) || !part_iter->part_info->get_partition_id(part_iter->part_info, &part_id, &dummy)) return part_id; } part_iter->field_vals.cur= part_iter->field_vals.start; return NOT_A_PARTITION_ID; } /* Same as get_next_partition_via_walking, but for subpartitions */ static uint32 get_next_subpartition_via_walking(PARTITION_ITERATOR *part_iter) { Field *field= part_iter->part_info->subpart_field_array[0]; uint32 res; if (part_iter->field_vals.cur == part_iter->field_vals.end) { part_iter->field_vals.cur= part_iter->field_vals.start; return NOT_A_PARTITION_ID; } field->store(part_iter->field_vals.cur++, FALSE); if (part_iter->part_info->get_subpartition_id(part_iter->part_info, &res)) return NOT_A_PARTITION_ID; return res; } /* Create partition names SYNOPSIS create_partition_name() out:out Created partition name string in1 First part in2 Second part name_variant Normal, temporary or renamed partition name RETURN VALUE NONE DESCRIPTION This method is used to calculate the partition name, service routine to the del_ren_cre_table method. */ void create_partition_name(char *out, const char *in1, const char *in2, uint name_variant, bool translate) { char transl_part_name[FN_REFLEN]; const char *transl_part; if (translate) { tablename_to_filename(in2, transl_part_name, FN_REFLEN); transl_part= transl_part_name; } else transl_part= in2; if (name_variant == NORMAL_PART_NAME) strxmov(out, in1, "#P#", transl_part, NullS); else if (name_variant == TEMP_PART_NAME) strxmov(out, in1, "#P#", transl_part, "#TMP#", NullS); else if (name_variant == RENAMED_PART_NAME) strxmov(out, in1, "#P#", transl_part, "#REN#", NullS); } /* Create subpartition name SYNOPSIS create_subpartition_name() out:out Created partition name string in1 First part in2 Second part in3 Third part name_variant Normal, temporary or renamed partition name RETURN VALUE NONE DESCRIPTION This method is used to calculate the subpartition name, service routine to the del_ren_cre_table method. */ void create_subpartition_name(char *out, const char *in1, const char *in2, const char *in3, uint name_variant) { char transl_part_name[FN_REFLEN], transl_subpart_name[FN_REFLEN]; tablename_to_filename(in2, transl_part_name, FN_REFLEN); tablename_to_filename(in3, transl_subpart_name, FN_REFLEN); if (name_variant == NORMAL_PART_NAME) strxmov(out, in1, "#P#", transl_part_name, "#SP#", transl_subpart_name, NullS); else if (name_variant == TEMP_PART_NAME) strxmov(out, in1, "#P#", transl_part_name, "#SP#", transl_subpart_name, "#TMP#", NullS); else if (name_variant == RENAMED_PART_NAME) strxmov(out, in1, "#P#", transl_part_name, "#SP#", transl_subpart_name, "#REN#", NullS); } #endif