diff options
Diffstat (limited to 'sql')
| -rw-r--r-- | sql/sql_select.cc | 10 | ||||
| -rw-r--r-- | sql/sql_table.cc | 44 |
2 files changed, 37 insertions, 17 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 1c8ff12eb92..2e28663e383 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -6436,7 +6436,15 @@ make_join_readinfo(JOIN *join, ulonglong options) else if (!table->covering_keys.is_clear_all() && !(tab->select && tab->select->quick)) { // Only read index tree - tab->index=find_shortest_key(table, & table->covering_keys); + /* + See bug #26447: "Using the clustered index for a table scan + is always faster than using a secondary index". + */ + if (table->s->primary_key != MAX_KEY && + table->file->primary_key_is_clustered()) + tab->index= table->s->primary_key; + else + tab->index=find_shortest_key(table, & table->covering_keys); tab->read_first_record= join_read_first; tab->type=JT_NEXT; // Read with index_first / index_next } diff --git a/sql/sql_table.cc b/sql/sql_table.cc index e6d84d0ef45..d63a6d7d3fc 100644 --- a/sql/sql_table.cc +++ b/sql/sql_table.cc @@ -6813,23 +6813,35 @@ copy_data_between_tables(TABLE *from,TABLE *to, if (order) { - from->sort.io_cache=(IO_CACHE*) my_malloc(sizeof(IO_CACHE), - MYF(MY_FAE | MY_ZEROFILL)); - bzero((char*) &tables,sizeof(tables)); - tables.table= from; - tables.alias= tables.table_name= from->s->table_name.str; - tables.db= from->s->db.str; - error=1; + if (to->s->primary_key != MAX_KEY && to->file->primary_key_is_clustered()) + { + char warn_buff[MYSQL_ERRMSG_SIZE]; + my_snprintf(warn_buff, sizeof(warn_buff), + "ORDER BY ignored as there is a user-defined clustered index" + " in the table '%-.192s'", from->s->table_name.str); + push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN, ER_UNKNOWN_ERROR, + warn_buff); + } + else + { + from->sort.io_cache=(IO_CACHE*) my_malloc(sizeof(IO_CACHE), + MYF(MY_FAE | MY_ZEROFILL)); + bzero((char *) &tables, sizeof(tables)); + tables.table= from; + tables.alias= tables.table_name= from->s->table_name.str; + tables.db= from->s->db.str; + error= 1; - if (thd->lex->select_lex.setup_ref_array(thd, order_num) || - setup_order(thd, thd->lex->select_lex.ref_pointer_array, - &tables, fields, all_fields, order) || - !(sortorder=make_unireg_sortorder(order, &length, NULL)) || - (from->sort.found_records = filesort(thd, from, sortorder, length, - (SQL_SELECT *) 0, HA_POS_ERROR, 1, - &examined_rows)) == - HA_POS_ERROR) - goto err; + if (thd->lex->select_lex.setup_ref_array(thd, order_num) || + setup_order(thd, thd->lex->select_lex.ref_pointer_array, + &tables, fields, all_fields, order) || + !(sortorder= make_unireg_sortorder(order, &length, NULL)) || + (from->sort.found_records= filesort(thd, from, sortorder, length, + (SQL_SELECT *) 0, HA_POS_ERROR, + 1, &examined_rows)) == + HA_POS_ERROR) + goto err; + } }; /* Tell handler that we have values for all columns in the to table */ |