diff options
Diffstat (limited to 'sql/sql_delete.cc')
| -rw-r--r-- | sql/sql_delete.cc | 678 |
1 files changed, 411 insertions, 267 deletions
diff --git a/sql/sql_delete.cc b/sql/sql_delete.cc index e37792141f5..93ec11ca063 100644 --- a/sql/sql_delete.cc +++ b/sql/sql_delete.cc @@ -44,6 +44,9 @@ // end_read_record #include "sql_insert.h" // fix_rownum_pointers #include "sql_partition.h" // make_used_partitions_str +#ifdef WITH_WSREP +#include "wsrep_mysqld.h" +#endif #define MEM_STRIP_BUF_SIZE ((size_t) thd->variables.sortbuff_size) @@ -103,7 +106,7 @@ bool Update_plan::save_explain_data_intern(MEM_ROOT *mem_root, bool is_analyze) { explain->select_type= "SIMPLE"; - explain->table_name.append(&table->pos_in_table_list->alias); + explain->table_name.append(table->alias); explain->impossible_where= false; explain->no_partitions= false; @@ -295,123 +298,85 @@ int TABLE::delete_row() /** - Implement DELETE SQL word. + @brief Special handling of single-table deletes after prepare phase - @note Like implementations of other DDL/DML in MySQL, this function - relies on the caller to close the thread tables. This is done in the - end of dispatch_command(). + @param thd global context the processed statement + @returns false on success, true on error */ -bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds, - SQL_I_List<ORDER> *order_list, ha_rows limit, - ulonglong options, select_result *result) +bool Sql_cmd_delete::delete_from_single_table(THD *thd) { - bool will_batch= FALSE; - int error, loc_error; - TABLE *table; - SQL_SELECT *select=0; - SORT_INFO *file_sort= 0; - READ_RECORD info; - bool using_limit=limit != HA_POS_ERROR; - bool transactional_table, safe_update, const_cond; - bool const_cond_result; - bool return_error= 0; - ha_rows deleted= 0; - bool reverse= FALSE; - bool has_triggers= false; - ORDER *order= (ORDER *) ((order_list && order_list->elements) ? - order_list->first : NULL); - SELECT_LEX *select_lex= thd->lex->first_select_lex(); - SELECT_LEX *returning= thd->lex->has_returning() ? thd->lex->returning() : 0; + int error; + int loc_error; + bool transactional_table; + bool const_cond; + bool safe_update; + bool const_cond_result; + bool return_error= 0; + TABLE *table; + SQL_SELECT *select= 0; + SORT_INFO *file_sort= 0; + READ_RECORD info; + ha_rows deleted= 0; + bool reverse= FALSE; + bool binlog_is_row; killed_state killed_status= NOT_KILLED; THD::enum_binlog_query_type query_type= THD::ROW_QUERY_TYPE; - bool binlog_is_row; - Explain_delete *explain; + bool will_batch= FALSE; + + bool has_triggers= false; + SELECT_LEX_UNIT *unit = &lex->unit; + SELECT_LEX *select_lex= unit->first_select(); + SELECT_LEX *returning= thd->lex->has_returning() ? thd->lex->returning() : 0; + TABLE_LIST *const table_list = select_lex->get_table_list(); + ulonglong options= select_lex->options; + ORDER *order= select_lex->order_list.first; + COND *conds= select_lex->join->conds; + ha_rows limit= unit->lim.get_select_limit(); + bool using_limit= limit != HA_POS_ERROR; + Delete_plan query_plan(thd->mem_root); + Explain_delete *explain; Unique * deltempfile= NULL; bool delete_record= false; - bool delete_while_scanning; + bool delete_while_scanning= table_list->delete_while_scanning; bool portion_of_time_through_update; - DBUG_ENTER("mysql_delete"); + + DBUG_ENTER("Sql_cmd_delete::delete_single_table"); query_plan.index= MAX_KEY; query_plan.using_filesort= FALSE; - create_explain_query(thd->lex, thd->mem_root); - if (open_and_lock_tables(thd, table_list, TRUE, 0)) - DBUG_RETURN(TRUE); - THD_STAGE_INFO(thd, stage_init_update); const bool delete_history= table_list->vers_conditions.delete_history; DBUG_ASSERT(!(delete_history && table_list->period_conditions.is_set())); - if (thd->lex->handle_list_of_derived(table_list, DT_MERGE_FOR_INSERT)) - DBUG_RETURN(TRUE); - if (thd->lex->handle_list_of_derived(table_list, DT_PREPARE)) - DBUG_RETURN(TRUE); + if (table_list->handle_derived(thd->lex, DT_MERGE_FOR_INSERT)) + DBUG_RETURN(1); + if (table_list->handle_derived(thd->lex, DT_PREPARE)) + DBUG_RETURN(1); + + table= table_list->table; if (!table_list->single_table_updatable()) { my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias.str, "DELETE"); DBUG_RETURN(TRUE); } - if (!(table= table_list->table) || !table->is_created()) + + if (!table || !table->is_created()) { my_error(ER_VIEW_DELETE_MERGE_VIEW, MYF(0), table_list->view_db.str, table_list->view_name.str); DBUG_RETURN(TRUE); } - table->map=1; + query_plan.select_lex= thd->lex->first_select_lex(); query_plan.table= table; thd->lex->promote_select_describe_flag_if_needed(); - if (mysql_prepare_delete(thd, table_list, &conds, &delete_while_scanning)) - DBUG_RETURN(TRUE); - - if (table_list->has_period()) - { - if (!table_list->period_conditions.start.item->const_item() - || !table_list->period_conditions.end.item->const_item()) - { - my_error(ER_NOT_CONSTANT_EXPRESSION, MYF(0), "FOR PORTION OF"); - DBUG_RETURN(true); - } - } - - if (delete_history) - table->vers_write= false; - - if (returning) - (void) result->prepare(returning->item_list, NULL); - - if (thd->lex->current_select->first_cond_optimization) - { - thd->lex->current_select->save_leaf_tables(thd); - thd->lex->current_select->first_cond_optimization= 0; - } - /* check ORDER BY even if it can be ignored */ - if (order) - { - TABLE_LIST tables; - List<Item> fields; - List<Item> all_fields; - - bzero((char*) &tables,sizeof(tables)); - tables.table = table; - tables.alias = table_list->alias; - - if (select_lex->setup_ref_array(thd, order_list->elements) || - setup_order(thd, select_lex->ref_pointer_array, &tables, - fields, all_fields, order)) - { - free_underlaid_joins(thd, thd->lex->first_select_lex()); - DBUG_RETURN(TRUE); - } - } - /* Apply the IN=>EXISTS transformation to all subqueries and optimize them. */ if (select_lex->optimize_unflattened_subqueries(false)) DBUG_RETURN(TRUE); @@ -1017,90 +982,6 @@ got_error: } -/* - Prepare items in DELETE statement - - SYNOPSIS - mysql_prepare_delete() - thd - thread handler - table_list - global/local table list - conds - conditions - - RETURN VALUE - FALSE OK - TRUE error -*/ -int mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, Item **conds, - bool *delete_while_scanning) -{ - Item *fake_conds= 0; - SELECT_LEX *select_lex= thd->lex->first_select_lex(); - DBUG_ENTER("mysql_prepare_delete"); - List<Item> all_fields; - - *delete_while_scanning= true; - thd->lex->allow_sum_func.clear_all(); - if (setup_tables_and_check_access(thd, &select_lex->context, - &select_lex->top_join_list, table_list, - select_lex->leaf_tables, FALSE, - DELETE_ACL, SELECT_ACL, TRUE)) - DBUG_RETURN(TRUE); - - if (table_list->vers_conditions.is_set() && table_list->is_view_or_derived()) - { - my_error(ER_IT_IS_A_VIEW, MYF(0), table_list->table_name.str); - DBUG_RETURN(true); - } - - if (table_list->has_period()) - { - if (table_list->is_view_or_derived()) - { - my_error(ER_IT_IS_A_VIEW, MYF(0), table_list->table_name.str); - DBUG_RETURN(true); - } - - if (select_lex->period_setup_conds(thd, table_list)) - DBUG_RETURN(true); - } - - DBUG_ASSERT(table_list->table); - // conds could be cached from previous SP call - DBUG_ASSERT(!table_list->vers_conditions.need_setup() || - !*conds || thd->stmt_arena->is_stmt_execute()); - if (select_lex->vers_setup_conds(thd, table_list)) - DBUG_RETURN(TRUE); - - *conds= select_lex->where; - - if (setup_returning_fields(thd, table_list) || - setup_conds(thd, table_list, select_lex->leaf_tables, conds) || - setup_ftfuncs(select_lex)) - DBUG_RETURN(TRUE); - if (!table_list->single_table_updatable() || - check_key_in_view(thd, table_list)) - { - my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias.str, "DELETE"); - DBUG_RETURN(TRUE); - } - - /* - Application-time periods: if FOR PORTION OF ... syntax used, DELETE - statement could issue delete_row's mixed with write_row's. This causes - problems for myisam and corrupts table, if deleting while scanning. - */ - if (table_list->has_period() - || unique_table(thd, table_list, table_list->next_global, 0)) - *delete_while_scanning= false; - - if (select_lex->inner_refs_list.elements && - fix_inner_refs(thd, all_fields, select_lex, select_lex->ref_pointer_array)) - DBUG_RETURN(TRUE); - - select_lex->fix_prepare_information(thd, conds, &fake_conds); - DBUG_RETURN(FALSE); -} - /*************************************************************************** Delete multiple tables from join @@ -1113,106 +994,6 @@ extern "C" int refpos_order_cmp(void* arg, const void *a,const void *b) return file->cmp_ref((const uchar*)a, (const uchar*)b); } -/* - make delete specific preparation and checks after opening tables - - SYNOPSIS - mysql_multi_delete_prepare() - thd thread handler - - RETURN - FALSE OK - TRUE Error -*/ - -int mysql_multi_delete_prepare(THD *thd) -{ - LEX *lex= thd->lex; - TABLE_LIST *aux_tables= lex->auxiliary_table_list.first; - TABLE_LIST *target_tbl; - DBUG_ENTER("mysql_multi_delete_prepare"); - - if (mysql_handle_derived(lex, DT_INIT)) - DBUG_RETURN(TRUE); - if (mysql_handle_derived(lex, DT_MERGE_FOR_INSERT)) - DBUG_RETURN(TRUE); - if (mysql_handle_derived(lex, DT_PREPARE)) - DBUG_RETURN(TRUE); - /* - setup_tables() need for VIEWs. JOIN::prepare() will not do it second - time. - - lex->query_tables also point on local list of DELETE SELECT_LEX - */ - if (setup_tables_and_check_access(thd, - &thd->lex->first_select_lex()->context, - &thd->lex->first_select_lex()-> - top_join_list, - lex->query_tables, - lex->first_select_lex()->leaf_tables, - FALSE, DELETE_ACL, SELECT_ACL, FALSE)) - DBUG_RETURN(TRUE); - - /* - Multi-delete can't be constructed over-union => we always have - single SELECT on top and have to check underlying SELECTs of it - */ - lex->first_select_lex()->set_unique_exclude(); - /* Fix tables-to-be-deleted-from list to point at opened tables */ - for (target_tbl= (TABLE_LIST*) aux_tables; - target_tbl; - target_tbl= target_tbl->next_local) - { - - target_tbl->table= target_tbl->correspondent_table->table; - if (target_tbl->correspondent_table->is_multitable()) - { - my_error(ER_VIEW_DELETE_MERGE_VIEW, MYF(0), - target_tbl->correspondent_table->view_db.str, - target_tbl->correspondent_table->view_name.str); - DBUG_RETURN(TRUE); - } - - if (!target_tbl->correspondent_table->single_table_updatable() || - check_key_in_view(thd, target_tbl->correspondent_table)) - { - my_error(ER_NON_UPDATABLE_TABLE, MYF(0), - target_tbl->table_name.str, "DELETE"); - DBUG_RETURN(TRUE); - } - } - - for (target_tbl= (TABLE_LIST*) aux_tables; - target_tbl; - target_tbl= target_tbl->next_local) - { - /* - Check that table from which we delete is not used somewhere - inside subqueries/view. - */ - { - TABLE_LIST *duplicate; - if ((duplicate= unique_table(thd, target_tbl->correspondent_table, - lex->query_tables, 0))) - { - update_non_unique_table_error(target_tbl->correspondent_table, - "DELETE", duplicate); - DBUG_RETURN(TRUE); - } - } - } - /* - Reset the exclude flag to false so it doesn't interfare - with further calls to unique_table - */ - lex->first_select_lex()->exclude_from_table_unique_test= FALSE; - - if (lex->save_prep_leaf_tables()) - DBUG_RETURN(TRUE); - - DBUG_RETURN(FALSE); -} - multi_delete::multi_delete(THD *thd_arg, TABLE_LIST *dt, uint num_of_tables_arg): select_result_interceptor(thd_arg), delete_tables(dt), deleted(0), found(0), @@ -1338,6 +1119,8 @@ multi_delete::~multi_delete() table_being_deleted= table_being_deleted->next_local) { TABLE *table= table_being_deleted->table; + if (!table) + continue; table->no_keyread=0; table->no_cache= 0; } @@ -1667,3 +1450,364 @@ bool multi_delete::send_eof() } return 0; } + + +/** + @brief Remove ORDER BY from DELETE if it's used without limit clause +*/ + +void Sql_cmd_delete::remove_order_by_without_limit(THD *thd) +{ + SELECT_LEX *const select_lex = thd->lex->first_select_lex(); + if (select_lex->order_list.elements && + !select_lex->limit_params.select_limit) + select_lex->order_list.empty(); +} + + +/** + @brief Check whether processing to multi-table delete is prohibited + + @param thd global context the processed statement + @returns true if processing as multitable is prohibited, false otherwise + + @todo + Introduce handler level flag for storage engines that would prohibit + such conversion for any single-table delete. +*/ + +bool Sql_cmd_delete::processing_as_multitable_delete_prohibited(THD *thd) +{ + SELECT_LEX *const select_lex = thd->lex->first_select_lex(); + return + ((select_lex->order_list.elements && + select_lex->limit_params.select_limit) || + thd->lex->has_returning()); +} + + +/** + @brief Perform precheck of table privileges for delete statements + + @param thd global context the processed statement + @returns false on success, true on error +*/ + +bool Sql_cmd_delete::precheck(THD *thd) +{ + if (!multitable) + { + if (delete_precheck(thd, lex->query_tables)) + return true; + } + else + { + if (multi_delete_precheck(thd, lex->query_tables)) + return true; + } + +#ifdef WITH_WSREP + WSREP_SYNC_WAIT(thd, WSREP_SYNC_WAIT_BEFORE_UPDATE_DELETE); +#endif + + return false; + +#ifdef WITH_WSREP +wsrep_error_label: +#endif + return true; +} + + +/** + @brief Perform context analysis for delete statements + + @param thd global context the processed statement + @returns false on success, true on error + + @note + The main bulk of the context analysis actions for a delete statement + is performed by a call of JOIN::prepare(). +*/ + +bool Sql_cmd_delete::prepare_inner(THD *thd) +{ + int err= 0; + TABLE_LIST *target_tbl; + JOIN *join; + SELECT_LEX *const select_lex = thd->lex->first_select_lex(); + TABLE_LIST *const table_list = select_lex->get_table_list(); + TABLE_LIST *aux_tables= thd->lex->auxiliary_table_list.first; + ulonglong select_options= select_lex->options; + bool free_join= 1; + SELECT_LEX *returning= thd->lex->has_returning() ? thd->lex->returning() : 0; + const bool delete_history= table_list->vers_conditions.delete_history; + DBUG_ASSERT(!(delete_history && table_list->period_conditions.is_set())); + + DBUG_ENTER("Sql_cmd_delete::prepare_inner"); + + (void) read_statistics_for_tables_if_needed(thd, table_list); + + THD_STAGE_INFO(thd, stage_init_update); + + { + if (mysql_handle_derived(lex, DT_INIT)) + DBUG_RETURN(TRUE); + if (mysql_handle_derived(lex, DT_MERGE_FOR_INSERT)) + DBUG_RETURN(TRUE); + if (mysql_handle_derived(lex, DT_PREPARE)) + DBUG_RETURN(TRUE); + } + + if (!(result= new (thd->mem_root) multi_delete(thd, aux_tables, + lex->table_count_update))) + { + DBUG_RETURN(TRUE); + } + + table_list->delete_while_scanning= true; + + if (!multitable && !table_list->single_table_updatable()) + { + my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias.str, "DELETE"); + DBUG_RETURN(TRUE); + } + + if (!multitable && (!table_list->table || !table_list->table->is_created())) + { + my_error(ER_VIEW_DELETE_MERGE_VIEW, MYF(0), + table_list->view_db.str, table_list->view_name.str); + DBUG_RETURN(TRUE); + } + + if (setup_tables_and_check_access(thd, &select_lex->context, + &select_lex->top_join_list, + table_list, select_lex->leaf_tables, + false, DELETE_ACL, SELECT_ACL, true)) + DBUG_RETURN(TRUE); + + if (setup_tables(thd, &select_lex->context, &select_lex->top_join_list, + table_list, select_lex->leaf_tables, false, false)) + DBUG_RETURN(TRUE); + + if (!multitable) + { + if (table_list->vers_conditions.is_set() && table_list->is_view_or_derived()) + { + my_error(ER_IT_IS_A_VIEW, MYF(0), table_list->table_name.str); + DBUG_RETURN(true); + } + + if (!multitable) + { + TABLE_LIST *update_source_table= 0; + if (((update_source_table=unique_table(thd, table_list, + table_list->next_global, 0)) || + table_list->is_multitable())) + { + DBUG_ASSERT(update_source_table || table_list->view != 0); + if (!table_list->is_multitable() && + !processing_as_multitable_delete_prohibited(thd)) + { + multitable= true; + remove_order_by_without_limit(thd); + } + } + } + + if (table_list->has_period()) + { + if (table_list->is_view_or_derived()) + { + my_error(ER_IT_IS_A_VIEW, MYF(0), table_list->table_name.str); + DBUG_RETURN(true); + } + + if (select_lex->period_setup_conds(thd, table_list)) + DBUG_RETURN(true); + } + + if (select_lex->vers_setup_conds(thd, table_list)) + DBUG_RETURN(TRUE); + /* + Application-time periods: if FOR PORTION OF ... syntax used, DELETE + statement could issue delete_row's mixed with write_row's. This causes + problems for myisam and corrupts table, if deleting while scanning. + */ + if (table_list->has_period() + || unique_table(thd, table_list, table_list->next_global, 0)) + table_list->delete_while_scanning= false; + } + + { + if (thd->lex->describe) + select_options|= SELECT_DESCRIBE; + + /* + When in EXPLAIN, delay deleting the joins so that they are still + available when we're producing EXPLAIN EXTENDED warning text. + */ + if (select_options & SELECT_DESCRIBE) + free_join= 0; + select_options|= + SELECT_NO_JOIN_CACHE | SELECT_NO_UNLOCK | OPTION_SETUP_TABLES_DONE; + + if (!(join= new (thd->mem_root) JOIN(thd, empty_list, + select_options, result))) + DBUG_RETURN(TRUE); + THD_STAGE_INFO(thd, stage_init); + select_lex->join= join; + thd->lex->used_tables=0; + if ((err= join->prepare(table_list, select_lex->where, + select_lex->order_list.elements, + select_lex->order_list.first, + false, NULL, NULL, NULL, + select_lex, &lex->unit))) + + { + goto err; + } + + if (!multitable && + select_lex->sj_subselects.elements) + multitable= true; + } + + if (multitable) + { + /* + Multi-delete can't be constructed over-union => we always have + single SELECT on top and have to check underlying SELECTs of it + */ + lex->first_select_lex()->set_unique_exclude(); + /* Fix tables-to-be-deleted-from list to point at opened tables */ + for (target_tbl= (TABLE_LIST*) aux_tables; + target_tbl; + target_tbl= target_tbl->next_local) + { + target_tbl->table= target_tbl->correspondent_table->table; + if (target_tbl->correspondent_table->is_multitable()) + { + my_error(ER_VIEW_DELETE_MERGE_VIEW, MYF(0), + target_tbl->correspondent_table->view_db.str, + target_tbl->correspondent_table->view_name.str); + DBUG_RETURN(TRUE); + } + + if (!target_tbl->correspondent_table->single_table_updatable() || + check_key_in_view(thd, target_tbl->correspondent_table)) + { + my_error(ER_NON_UPDATABLE_TABLE, MYF(0), + target_tbl->table_name.str, "DELETE"); + DBUG_RETURN(TRUE); + } + } + + /* + Reset the exclude flag to false so it doesn't interfare + with further calls to unique_table + */ + lex->first_select_lex()->exclude_from_table_unique_test= FALSE; + } + + if (!multitable && table_list->has_period()) + { + if (!table_list->period_conditions.start.item->const_item() + || !table_list->period_conditions.end.item->const_item()) + { + my_error(ER_NOT_CONSTANT_EXPRESSION, MYF(0), "FOR PORTION OF"); + DBUG_RETURN(true); + } + } + + if (delete_history) + table_list->table->vers_write= false; + + if (setup_returning_fields(thd, table_list) || + setup_ftfuncs(select_lex)) + goto err; + + free_join= false; + + if (returning) + (void) result->prepare(returning->item_list, NULL); + +err: + + if (free_join) + { + THD_STAGE_INFO(thd, stage_end); + err|= (int)(select_lex->cleanup()); + DBUG_RETURN(err || thd->is_error()); + } + DBUG_RETURN(err); + +} + + +/** + @brief Perform optimization and execution actions needed for deletes + + @param thd global context the processed statement + @returns false on success, true on error +*/ + +bool Sql_cmd_delete::execute_inner(THD *thd) +{ + if (!multitable) + { + if (lex->has_returning()) + { + select_result *sel_result= NULL; + delete result; + /* This is DELETE ... RETURNING. It will return output to the client */ + if (thd->lex->analyze_stmt) + { + /* + Actually, it is ANALYZE .. DELETE .. RETURNING. We need to produce + output and then discard it. + */ + sel_result= new (thd->mem_root) select_send_analyze(thd); + save_protocol= thd->protocol; + thd->protocol= new Protocol_discard(thd); + } + else + { + if (!lex->result && !(sel_result= new (thd->mem_root) select_send(thd))) + return true; + } + result= lex->result ? lex->result : sel_result; + } + } + + bool res= multitable ? Sql_cmd_dml::execute_inner(thd) + : delete_from_single_table(thd); + + res|= thd->is_error(); + + if (save_protocol) + { + delete thd->protocol; + thd->protocol= save_protocol; + } + { + if (unlikely(res)) + { + if (multitable) + result->abort_result_set(); + } + else + { + if (thd->lex->describe || thd->lex->analyze_stmt) + res= thd->lex->explain->send_explain(thd); + } + } + + if (result) + { + res= false; + delete result; + } + + return res; +} |