diff options
Diffstat (limited to 'sql/sql_delete.cc')
| -rw-r--r-- | sql/sql_delete.cc | 104 |
1 files changed, 78 insertions, 26 deletions
diff --git a/sql/sql_delete.cc b/sql/sql_delete.cc index eb5f0d7a477..a9275bd39fd 100644 --- a/sql/sql_delete.cc +++ b/sql/sql_delete.cc @@ -45,6 +45,8 @@ // end_read_record #include "sql_partition.h" // make_used_partitions_str +#define MEM_STRIP_BUF_SIZE thd->variables.sortbuff_size + /* @brief Print query plan of a single-table DELETE command @@ -212,6 +214,22 @@ void Update_plan::save_explain_data_intern(MEM_ROOT *mem_root, } +static bool record_should_be_deleted(THD *thd, TABLE *table, SQL_SELECT *sel, + Explain_delete *explain) +{ + explain->tracker.on_record_read(); + thd->inc_examined_row_count(1); + if (table->vfield) + (void) table->update_virtual_fields(table->file, VCOL_UPDATE_FOR_DELETE); + if (!sel || sel->skip_record(thd) > 0) + { + explain->tracker.on_record_after_where(); + return true; + } + return false; +} + + /** Implement DELETE SQL word. @@ -244,9 +262,12 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds, bool with_select= !select_lex->item_list.is_empty(); Explain_delete *explain; Delete_plan query_plan(thd->mem_root); + Unique * deltempfile= NULL; + bool delete_record, delete_while_scanning; + DBUG_ENTER("mysql_delete"); + query_plan.index= MAX_KEY; query_plan.using_filesort= FALSE; - DBUG_ENTER("mysql_delete"); create_explain_query(thd->lex, thd->mem_root); if (open_and_lock_tables(thd, table_list, TRUE, 0)) @@ -275,7 +296,8 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds, query_plan.updating_a_view= MY_TEST(table_list->view); if (mysql_prepare_delete(thd, table_list, select_lex->with_wild, - select_lex->item_list, &conds)) + select_lex->item_list, &conds, + &delete_while_scanning)) DBUG_RETURN(TRUE); if (with_select) @@ -556,16 +578,48 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds, explain= (Explain_delete*)thd->lex->explain->get_upd_del_plan(); explain->tracker.on_scan_init(); + if (!delete_while_scanning) + { + /* + The table we are going to delete appears in subqueries in the where + clause. Instead of deleting the rows, first mark them deleted. + */ + ha_rows tmplimit=limit; + deltempfile= new (thd->mem_root) Unique (refpos_order_cmp, table->file, + table->file->ref_length, + MEM_STRIP_BUF_SIZE); + while (!(error=info.read_record(&info)) && !thd->killed && + ! thd->is_error()) + { + if (record_should_be_deleted(thd, table, select, explain)) + { + table->file->position(table->record[0]); + if ((error= deltempfile->unique_add((char*) table->file->ref))) + { + error= 1; + goto terminate_delete; + } + if (!--tmplimit && using_limit) + break; + } + } + end_read_record(&info); + if (deltempfile->get(table) || table->file->ha_index_or_rnd_end() || + init_read_record(&info, thd, table, 0, &deltempfile->sort, 0, 1, false)) + { + error= 1; + goto terminate_delete; + } + delete_record= true; + } + while (!(error=info.read_record(&info)) && !thd->killed && - ! thd->is_error()) + ! thd->is_error()) { - explain->tracker.on_record_read(); - thd->inc_examined_row_count(1); - if (table->vfield) - (void) table->update_virtual_fields(table->file, VCOL_UPDATE_FOR_DELETE); - if (!select || select->skip_record(thd) > 0) + if (delete_while_scanning) + delete_record= record_should_be_deleted(thd, table, select, explain); + if (delete_record) { - explain->tracker.on_record_after_where(); if (table->triggers && table->triggers->process_triggers(thd, TRG_EVENT_DELETE, TRG_ACTION_BEFORE, FALSE)) @@ -616,6 +670,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds, else break; } +terminate_delete: killed_status= thd->killed; if (killed_status != NOT_KILLED || thd->is_error()) error= 1; // Aborted @@ -647,6 +702,8 @@ cleanup: thd->lex->current_select->first_cond_optimization= 0; } + delete deltempfile; + deltempfile=NULL; delete select; select= NULL; transactional_table= table->file->has_transactions(); @@ -746,13 +803,15 @@ l TRUE error */ int mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, - uint wild_num, List<Item> &field_list, Item **conds) + uint wild_num, List<Item> &field_list, Item **conds, + bool *delete_while_scanning) { Item *fake_conds= 0; SELECT_LEX *select_lex= &thd->lex->select_lex; DBUG_ENTER("mysql_prepare_delete"); List<Item> all_fields; + *delete_while_scanning= true; thd->lex->allow_sum_func= 0; if (setup_tables_and_check_access(thd, &thd->lex->select_lex.context, &thd->lex->select_lex.top_join_list, @@ -772,14 +831,9 @@ l my_error(ER_NON_UPDATABLE_TABLE, MYF(0), table_list->alias, "DELETE"); DBUG_RETURN(TRUE); } - { - TABLE_LIST *duplicate; - if ((duplicate= unique_table(thd, table_list, table_list->next_global, 0))) - { - update_non_unique_table_error(table_list, "DELETE", duplicate); - DBUG_RETURN(TRUE); - } - } + + if (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)) @@ -794,7 +848,6 @@ l Delete multiple tables from join ***************************************************************************/ -#define MEM_STRIP_BUF_SIZE current_thd->variables.sortbuff_size extern "C" int refpos_order_cmp(void* arg, const void *a,const void *b) { @@ -944,7 +997,7 @@ multi_delete::initialize_tables(JOIN *join) DBUG_RETURN(1); table_map tables_to_delete_from=0; - delete_while_scanning= 1; + delete_while_scanning= true; for (walk= delete_tables; walk; walk= walk->next_local) { TABLE_LIST *tbl= walk->correspondent_table->find_table_for_update(); @@ -957,7 +1010,7 @@ multi_delete::initialize_tables(JOIN *join) in join, we need to defer delete. So the delete doesn't interfers with the scaning of results. */ - delete_while_scanning= 0; + delete_while_scanning= false; } } @@ -993,7 +1046,7 @@ multi_delete::initialize_tables(JOIN *join) case send_data() shouldn't delete any rows a we may touch the rows in the deleted table many times */ - delete_while_scanning= 0; + delete_while_scanning= false; } } walk= delete_tables; @@ -1006,10 +1059,9 @@ multi_delete::initialize_tables(JOIN *join) for (;walk ;walk= walk->next_local) { TABLE *table=walk->table; - *tempfiles_ptr++= new Unique (refpos_order_cmp, - (void *) table->file, - table->file->ref_length, - MEM_STRIP_BUF_SIZE); + *tempfiles_ptr++= new (thd->mem_root) Unique (refpos_order_cmp, table->file, + table->file->ref_length, + MEM_STRIP_BUF_SIZE); } init_ftfuncs(thd, thd->lex->current_select, 1); DBUG_RETURN(thd->is_fatal_error != 0); |