/* Copyright (c) 2000, 2019, Oracle and/or its affiliates. Copyright (c) 2010, 2019, MariaDB 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ /* Delete of records tables. Multi-table deletes were introduced by Monty and Sinisa */ #include "mariadb.h" #include "sql_priv.h" #include "unireg.h" #include "sql_delete.h" #include "sql_cache.h" // query_cache_* #include "sql_base.h" // open_temprary_table #include "lock.h" // unlock_table_name #include "sql_view.h" // check_key_in_view, mysql_frm_type #include "sql_parse.h" // mysql_init_select #include "sql_acl.h" // *_ACL #include "filesort.h" // filesort #include "sql_handler.h" // mysql_ha_rm_tables #include "sql_select.h" #include "sp_head.h" #include "sql_trigger.h" #include "sql_statistics.h" #include "transaction.h" #include "records.h" // init_read_record, #include "filesort.h" #include "uniques.h" #include "sql_derived.h" // mysql_handle_derived // end_read_record #include "sql_partition.h" // make_used_partitions_str #define MEM_STRIP_BUF_SIZE ((size_t) thd->variables.sortbuff_size) /* @brief Print query plan of a single-table DELETE command @detail This function is used by EXPLAIN DELETE and by SHOW EXPLAIN when it is invoked on a running DELETE statement. */ Explain_delete* Delete_plan::save_explain_delete_data(MEM_ROOT *mem_root, THD *thd) { Explain_query *query= thd->lex->explain; Explain_delete *explain= new (mem_root) Explain_delete(mem_root, thd->lex->analyze_stmt); if (!explain) return 0; if (deleting_all_rows) { explain->deleting_all_rows= true; explain->select_type= "SIMPLE"; explain->rows= scanned_rows; } else { explain->deleting_all_rows= false; if (Update_plan::save_explain_data_intern(mem_root, explain, thd->lex->analyze_stmt)) return 0; } query->add_upd_del_plan(explain); return explain; } Explain_update* Update_plan::save_explain_update_data(MEM_ROOT *mem_root, THD *thd) { Explain_query *query= thd->lex->explain; Explain_update* explain= new (mem_root) Explain_update(mem_root, thd->lex->analyze_stmt); if (!explain) return 0; if (save_explain_data_intern(mem_root, explain, thd->lex->analyze_stmt)) return 0; query->add_upd_del_plan(explain); return explain; } bool Update_plan::save_explain_data_intern(MEM_ROOT *mem_root, Explain_update *explain, bool is_analyze) { explain->select_type= "SIMPLE"; explain->table_name.append(&table->pos_in_table_list->alias); explain->impossible_where= false; explain->no_partitions= false; if (impossible_where) { explain->impossible_where= true; return 0; } if (no_partitions) { explain->no_partitions= true; return 0; } if (is_analyze) table->file->set_time_tracker(&explain->table_tracker); select_lex->set_explain_type(TRUE); explain->select_type= select_lex->type; /* Partitions */ { #ifdef WITH_PARTITION_STORAGE_ENGINE partition_info *part_info; if ((part_info= table->part_info)) { make_used_partitions_str(mem_root, part_info, &explain->used_partitions, explain->used_partitions_list); explain->used_partitions_set= true; } else explain->used_partitions_set= false; #else /* just produce empty column if partitioning is not compiled in */ explain->used_partitions_set= false; #endif } /* Set jtype */ if (select && select->quick) { int quick_type= select->quick->get_type(); if ((quick_type == QUICK_SELECT_I::QS_TYPE_INDEX_MERGE) || (quick_type == QUICK_SELECT_I::QS_TYPE_INDEX_INTERSECT) || (quick_type == QUICK_SELECT_I::QS_TYPE_ROR_INTERSECT) || (quick_type == QUICK_SELECT_I::QS_TYPE_ROR_UNION)) explain->jtype= JT_INDEX_MERGE; else explain->jtype= JT_RANGE; } else { if (index == MAX_KEY) explain->jtype= JT_ALL; else explain->jtype= JT_NEXT; } explain->using_where= MY_TEST(select && select->cond); explain->where_cond= select? select->cond: NULL; if (using_filesort) if (!(explain->filesort_tracker= new (mem_root) Filesort_tracker(is_analyze))) return 1; explain->using_io_buffer= using_io_buffer; append_possible_keys(mem_root, explain->possible_keys, table, possible_keys); explain->quick_info= NULL; /* Calculate key_len */ if (select && select->quick) { explain->quick_info= select->quick->get_explain(mem_root); } else { if (index != MAX_KEY) { explain->key.set(mem_root, &table->key_info[index], table->key_info[index].key_length); } } explain->rows= scanned_rows; if (select && select->quick && select->quick->get_type() == QUICK_SELECT_I::QS_TYPE_RANGE) { explain_append_mrr_info((QUICK_RANGE_SELECT*)select->quick, &explain->mrr_type); } bool skip= updating_a_view; /* Save subquery children */ for (SELECT_LEX_UNIT *unit= select_lex->first_inner_unit(); unit; unit= unit->next_unit()) { if (skip) { skip= false; continue; } /* Display subqueries only if they are not parts of eliminated WHERE/ON clauses. */ if (!(unit->item && unit->item->eliminated)) explain->add_child(unit->first_select()->select_number); } return 0; } static bool record_should_be_deleted(THD *thd, TABLE *table, SQL_SELECT *sel, Explain_delete *explain, bool truncate_history) { 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; } inline int TABLE::delete_row() { if (!versioned(VERS_TIMESTAMP) || !vers_end_field()->is_max()) return file->ha_delete_row(record[0]); store_record(this, record[1]); vers_update_end(); return file->ha_update_row(record[1], record[0]); } /** Implement DELETE SQL word. @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(). */ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds, SQL_I_List *order_list, ha_rows limit, ulonglong options, select_result *result) { 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; ORDER *order= (ORDER *) ((order_list && order_list->elements) ? order_list->first : NULL); SELECT_LEX *select_lex= &thd->lex->select_lex; killed_state killed_status= NOT_KILLED; THD::enum_binlog_query_type query_type= THD::ROW_QUERY_TYPE; bool binlog_is_row; 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; 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; 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->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()) { 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->select_lex; query_plan.table= table; 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, &delete_while_scanning)) DBUG_RETURN(TRUE); if (delete_history) table->vers_write= false; if (with_select) (void) result->prepare(select_lex->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 fields; List 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->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); const_cond= (!conds || conds->const_item()); safe_update= MY_TEST(thd->variables.option_bits & OPTION_SAFE_UPDATES); if (safe_update && const_cond) { my_message(ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE, ER_THD(thd, ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE), MYF(0)); DBUG_RETURN(TRUE); } const_cond_result= const_cond && (!conds || conds->val_int()); if (unlikely(thd->is_error())) { /* Error evaluating val_int(). */ DBUG_RETURN(TRUE); } /* Test if the user wants to delete all rows and deletion doesn't have any side-effects (because of triggers), so we can use optimized handler::delete_all_rows() method. We can use delete_all_rows() if and only if: - We allow new functions (not using option --skip-new), and are not in safe mode (not using option --safe-mode) - There is no limit clause - The condition is constant - If there is a condition, then it it produces a non-zero value - If the current command is DELETE FROM with no where clause, then: - We should not be binlogging this statement in row-based, and - there should be no delete triggers associated with the table. */ has_triggers= (table->triggers && table->triggers->has_delete_triggers()); if (!with_select && !using_limit && const_cond_result && (!thd->is_current_stmt_binlog_format_row() && !has_triggers) && !table->versioned(VERS_TIMESTAMP)) { /* Update the table->file->stats.records number */ table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK); ha_rows const maybe_deleted= table->file->stats.records; DBUG_PRINT("debug", ("Trying to use delete_all_rows()")); query_plan.set_delete_all_rows(maybe_deleted); if (thd->lex->describe) goto produce_explain_and_leave; if (likely(!(error=table->file->ha_delete_all_rows()))) { /* If delete_all_rows() is used, it is not possible to log the query in row format, so we have to log it in statement format. */ query_type= THD::STMT_QUERY_TYPE; error= -1; deleted= maybe_deleted; if (!query_plan.save_explain_delete_data(thd->mem_root, thd)) error= 1; goto cleanup; } if (error != HA_ERR_WRONG_COMMAND) { table->file->print_error(error,MYF(0)); error=0; goto cleanup; } /* Handler didn't support fast delete; Delete rows one by one */ query_plan.cancel_delete_all_rows(); } if (conds) { Item::cond_result result; conds= conds->remove_eq_conds(thd, &result, true); if (result == Item::COND_FALSE) // Impossible where { limit= 0; query_plan.set_impossible_where(); if (thd->lex->describe || thd->lex->analyze_stmt) goto produce_explain_and_leave; } } #ifdef WITH_PARTITION_STORAGE_ENGINE if (prune_partitions(thd, table, conds)) { free_underlaid_joins(thd, select_lex); query_plan.set_no_partitions(); if (thd->lex->describe || thd->lex->analyze_stmt) goto produce_explain_and_leave; my_ok(thd, 0); DBUG_RETURN(0); } #endif /* Update the table->file->stats.records number */ table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK); set_statistics_for_table(thd, table); table->covering_keys.clear_all(); table->quick_keys.clear_all(); // Can't use 'only index' select=make_select(table, 0, 0, conds, (SORT_INFO*) 0, 0, &error); if (unlikely(error)) DBUG_RETURN(TRUE); if ((select && select->check_quick(thd, safe_update, limit)) || !limit) { query_plan.set_impossible_where(); if (thd->lex->describe || thd->lex->analyze_stmt) goto produce_explain_and_leave; delete select; free_underlaid_joins(thd, select_lex); /* Error was already created by quick select evaluation (check_quick()). TODO: Add error code output parameter to Item::val_xxx() methods. Currently they rely on the user checking DA for errors when unwinding the stack after calling Item::val_xxx(). */ if (unlikely(thd->is_error())) DBUG_RETURN(TRUE); my_ok(thd, 0); DBUG_RETURN(0); // Nothing to delete } /* If running in safe sql mode, don't allow updates without keys */ if (table->quick_keys.is_clear_all()) { thd->set_status_no_index_used(); if (safe_update && !using_limit) { delete select; free_underlaid_joins(thd, select_lex); my_message(ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE, ER_THD(thd, ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE), MYF(0)); DBUG_RETURN(TRUE); } } if (options & OPTION_QUICK) (void) table->file->extra(HA_EXTRA_QUICK); query_plan.scanned_rows= select? select->records: table->file->stats.records; if (order) { table->update_const_key_parts(conds); order= simple_remove_const(order, conds); if (select && select->quick && select->quick->unique_key_range()) { // Single row select (always "ordered") query_plan.using_filesort= FALSE; query_plan.index= MAX_KEY; } else { ha_rows scanned_limit= query_plan.scanned_rows; query_plan.index= get_index_for_order(order, table, select, limit, &scanned_limit, &query_plan.using_filesort, &reverse); if (!query_plan.using_filesort) query_plan.scanned_rows= scanned_limit; } } query_plan.select= select; query_plan.possible_keys= select? select->possible_keys: key_map(0); /* Ok, we have generated a query plan for the DELETE. - if we're running EXPLAIN DELETE, goto produce explain output - otherwise, execute the query plan */ if (thd->lex->describe) goto produce_explain_and_leave; if (!(explain= query_plan.save_explain_delete_data(thd->mem_root, thd))) goto got_error; ANALYZE_START_TRACKING(&explain->command_tracker); DBUG_EXECUTE_IF("show_explain_probe_delete_exec_start", dbug_serve_apcs(thd, 1);); if (!(select && select->quick)) status_var_increment(thd->status_var.delete_scan_count); binlog_is_row= thd->is_current_stmt_binlog_format_row(); DBUG_PRINT("info", ("binlog_is_row: %s", binlog_is_row ? "TRUE" : "FALSE")); /* We can use direct delete (delete that is done silently in the handler) if none of the following conditions are true: - There are triggers - There is binary logging - There is a virtual not stored column in the WHERE clause - ORDER BY or LIMIT - As this requires the rows to be deleted in a specific order - Note that Spider can handle ORDER BY and LIMIT in a cluster with one data node. These conditions are therefore checked in direct_delete_rows_init(). Direct delete does not require a WHERE clause Later we also ensure that we are only using one table (no sub queries) */ if ((table->file->ha_table_flags() & HA_CAN_DIRECT_UPDATE_AND_DELETE) && !has_triggers && !binlog_is_row && !with_select) { table->mark_columns_needed_for_delete(); if (!table->check_virtual_columns_marked_for_read()) { DBUG_PRINT("info", ("Trying direct delete")); if (select && select->cond && (select->cond->used_tables() == table->map)) { DBUG_ASSERT(!table->file->pushed_cond); if (!table->file->cond_push(select->cond)) table->file->pushed_cond= select->cond; } if (!table->file->direct_delete_rows_init()) { /* Direct deleting is supported */ DBUG_PRINT("info", ("Using direct delete")); THD_STAGE_INFO(thd, stage_updating); if (!(error= table->file->ha_direct_delete_rows(&deleted))) error= -1; goto terminate_delete; } } } if (query_plan.using_filesort) { { Filesort fsort(order, HA_POS_ERROR, true, select); DBUG_ASSERT(query_plan.index == MAX_KEY); Filesort_tracker *fs_tracker= thd->lex->explain->get_upd_del_plan()->filesort_tracker; if (!(file_sort= filesort(thd, table, &fsort, fs_tracker))) goto got_error; thd->inc_examined_row_count(file_sort->examined_rows); /* Filesort has already found and selected the rows we want to delete, so we don't need the where clause */ delete select; /* If we are not in DELETE ... RETURNING, we can free subqueries. (in DELETE ... RETURNING we can't, because the RETURNING part may have a subquery in it) */ if (!with_select) free_underlaid_joins(thd, select_lex); select= 0; } } /* If quick select is used, initialize it before retrieving rows. */ if (select && select->quick && select->quick->reset()) goto got_error; if (query_plan.index == MAX_KEY || (select && select->quick)) error= init_read_record(&info, thd, table, select, file_sort, 1, 1, FALSE); else error= init_read_record_idx(&info, thd, table, 1, query_plan.index, reverse); if (unlikely(error)) goto got_error; if (unlikely(init_ftfuncs(thd, select_lex, 1))) goto got_error; table->mark_columns_needed_for_delete(); if ((table->file->ha_table_flags() & HA_CAN_FORCE_BULK_DELETE) && !table->prepare_triggers_for_delete_stmt_or_event()) will_batch= !table->file->start_bulk_delete(); if (with_select) { if (unlikely(result->send_result_set_metadata(select_lex->item_list, Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF))) goto cleanup; } 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); THD_STAGE_INFO(thd, stage_searching_rows_for_update); while (!(error=info.read_record()) && !thd->killed && ! thd->is_error()) { if (record_should_be_deleted(thd, table, select, explain, delete_history)) { table->file->position(table->record[0]); if (unlikely((error= deltempfile->unique_add((char*) table->file->ref)))) { error= 1; goto terminate_delete; } if (!--tmplimit && using_limit) break; } } end_read_record(&info); if (unlikely(deltempfile->get(table)) || unlikely(table->file->ha_index_or_rnd_end()) || unlikely(init_read_record(&info, thd, table, 0, &deltempfile->sort, 0, 1, false))) { error= 1; goto terminate_delete; } delete_record= true; } THD_STAGE_INFO(thd, stage_updating); while (likely(!(error=info.read_record())) && likely(!thd->killed) && likely(!thd->is_error())) { if (delete_while_scanning) delete_record= record_should_be_deleted(thd, table, select, explain, delete_history); if (delete_record) { if (!delete_history && table->triggers && table->triggers->process_triggers(thd, TRG_EVENT_DELETE, TRG_ACTION_BEFORE, FALSE)) { error= 1; break; } if (with_select && result->send_data(select_lex->item_list) < 0) { error=1; break; } error= table->delete_row(); if (likely(!error)) { deleted++; if (!delete_history && table->triggers && table->triggers->process_triggers(thd, TRG_EVENT_DELETE, TRG_ACTION_AFTER, FALSE)) { error= 1; break; } if (!--limit && using_limit) { error= -1; break; } } else { table->file->print_error(error, MYF(thd->lex->ignore ? ME_JUST_WARNING : 0)); if (thd->is_error()) { error= 1; break; } } } /* Don't try unlocking the row if skip_record reported an error since in this case the transaction might have been rolled back already. */ else if (likely(!thd->is_error())) table->file->unlock_row(); // Row failed selection, release lock on it else break; } terminate_delete: killed_status= thd->killed; if (unlikely(killed_status != NOT_KILLED || thd->is_error())) error= 1; // Aborted if (will_batch && unlikely((loc_error= table->file->end_bulk_delete()))) { if (error != 1) table->file->print_error(loc_error,MYF(0)); error=1; } THD_STAGE_INFO(thd, stage_end); end_read_record(&info); if (options & OPTION_QUICK) (void) table->file->extra(HA_EXTRA_NORMAL); ANALYZE_STOP_TRACKING(&explain->command_tracker); cleanup: /* Invalidate the table in the query cache if something changed. This must be before binlog writing and ha_autocommit_... */ if (deleted) { query_cache_invalidate3(thd, table_list, 1); } if (thd->lex->current_select->first_cond_optimization) { thd->lex->current_select->save_leaf_tables(thd); thd->lex->current_select->first_cond_optimization= 0; } delete deltempfile; deltempfile=NULL; delete select; select= NULL; transactional_table= table->file->has_transactions(); if (!transactional_table && deleted > 0) thd->transaction.stmt.modified_non_trans_table= thd->transaction.all.modified_non_trans_table= TRUE; /* See similar binlogging code in sql_update.cc, for comments */ if (likely((error < 0) || thd->transaction.stmt.modified_non_trans_table)) { if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open()) { int errcode= 0; if (error < 0) thd->clear_error(); else errcode= query_error_code(thd, killed_status == NOT_KILLED); ScopedStatementReplication scoped_stmt_rpl( table->versioned(VERS_TRX_ID) ? thd : NULL); /* [binlog]: If 'handler::delete_all_rows()' was called and the storage engine does not inject the rows itself, we replicate statement-based; otherwise, 'ha_delete_row()' was used to delete specific rows which we might log row-based. */ int log_result= thd->binlog_query(query_type, thd->query(), thd->query_length(), transactional_table, FALSE, FALSE, errcode); if (log_result > 0) { error=1; } } } DBUG_ASSERT(transactional_table || !deleted || thd->transaction.stmt.modified_non_trans_table); if (likely(error < 0) || (thd->lex->ignore && !thd->is_error() && !thd->is_fatal_error)) { if (thd->lex->analyze_stmt) goto send_nothing_and_leave; if (with_select) result->send_eof(); else my_ok(thd, deleted); DBUG_PRINT("info",("%ld records deleted",(long) deleted)); } delete file_sort; free_underlaid_joins(thd, select_lex); if (table->file->pushed_cond) table->file->cond_pop(); DBUG_RETURN(error >= 0 || thd->is_error()); /* Special exits */ produce_explain_and_leave: /* We come here for various "degenerate" query plans: impossible WHERE, no-partitions-used, impossible-range, etc. */ if (!(query_plan.save_explain_delete_data(thd->mem_root, thd))) goto got_error; send_nothing_and_leave: /* ANALYZE DELETE jumps here. We can't send explain right here, because we might be using ANALYZE DELETE ...RETURNING, in which case we have Protocol_discard active. */ delete select; delete file_sort; free_underlaid_joins(thd, select_lex); if (table->file->pushed_cond) table->file->cond_pop(); DBUG_ASSERT(!return_error || thd->is_error() || thd->killed); DBUG_RETURN((return_error || thd->is_error() || thd->killed) ? 1 : 0); got_error: return_error= 1; goto send_nothing_and_leave; } /* Prepare items in DELETE statement SYNOPSIS mysql_prepare_delete() thd - thread handler table_list - global/local table list wild_num - number of wildcards used in optional SELECT clause field_list - list of items in optional SELECT clause conds - conditions RETURN VALUE FALSE OK TRUE error */ int mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, uint wild_num, List &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 all_fields; *delete_while_scanning= true; thd->lex->allow_sum_func.clear_all(); if (setup_tables_and_check_access(thd, &thd->lex->select_lex.context, &thd->lex->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); } DBUG_ASSERT(table_list->table); // conds could be cached from previous SP call DBUG_ASSERT(!table_list->vers_conditions.is_set() || !*conds || thd->stmt_arena->is_stmt_execute()); if (select_lex->vers_setup_conds(thd, table_list)) DBUG_RETURN(TRUE); *conds= select_lex->where; if ((wild_num && setup_wild(thd, table_list, field_list, NULL, wild_num, &select_lex->hidden_bit_fields)) || setup_fields(thd, Ref_ptr_array(), field_list, MARK_COLUMNS_READ, NULL, NULL, 0) || 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); } 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)) DBUG_RETURN(TRUE); select_lex->fix_prepare_information(thd, conds, &fake_conds); DBUG_RETURN(FALSE); } /*************************************************************************** Delete multiple tables from join ***************************************************************************/ extern "C" int refpos_order_cmp(void* arg, const void *a,const void *b) { handler *file= (handler*)arg; 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->select_lex.context, &thd->lex->select_lex.top_join_list, lex->query_tables, lex->select_lex.leaf_tables, FALSE, DELETE_ACL, SELECT_ACL, FALSE)) DBUG_RETURN(TRUE); if (lex->select_lex.handle_derived(thd->lex, DT_MERGE)) 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->select_lex.exclude_from_table_unique_test= TRUE; /* 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); } /* 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->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), num_of_tables(num_of_tables_arg), error(0), do_delete(0), transactional_tables(0), normal_tables(0), error_handled(0) { tempfiles= (Unique **) thd_arg->calloc(sizeof(Unique *) * num_of_tables); } int multi_delete::prepare(List &values, SELECT_LEX_UNIT *u) { DBUG_ENTER("multi_delete::prepare"); unit= u; do_delete= 1; THD_STAGE_INFO(thd, stage_deleting_from_main_table); SELECT_LEX *select_lex= u->first_select(); if (select_lex->first_cond_optimization) { if (select_lex->handle_derived(thd->lex, DT_MERGE)) DBUG_RETURN(TRUE); } DBUG_RETURN(0); } void multi_delete::prepare_to_read_rows() { /* see multi_update::prepare_to_read_rows() */ for (TABLE_LIST *walk= delete_tables; walk; walk= walk->next_local) { TABLE_LIST *tbl= walk->correspondent_table->find_table_for_update(); tbl->table->mark_columns_needed_for_delete(); } } bool multi_delete::initialize_tables(JOIN *join) { TABLE_LIST *walk; Unique **tempfiles_ptr; DBUG_ENTER("initialize_tables"); if (unlikely((thd->variables.option_bits & OPTION_SAFE_UPDATES) && error_if_full_join(join))) DBUG_RETURN(1); table_map tables_to_delete_from=0; delete_while_scanning= true; for (walk= delete_tables; walk; walk= walk->next_local) { TABLE_LIST *tbl= walk->correspondent_table->find_table_for_update(); tables_to_delete_from|= tbl->table->map; if (delete_while_scanning && unique_table(thd, tbl, join->tables_list, 0)) { /* If the table we are going to delete from appears in join, we need to defer delete. So the delete doesn't interfers with the scaning of results. */ delete_while_scanning= false; } } walk= delete_tables; for (JOIN_TAB *tab= first_linear_tab(join, WITHOUT_BUSH_ROOTS, WITH_CONST_TABLES); tab; tab= next_linear_tab(join, tab, WITHOUT_BUSH_ROOTS)) { if (!tab->bush_children && tab->table->map & tables_to_delete_from) { /* We are going to delete from this table */ TABLE *tbl=walk->table=tab->table; walk= walk->next_local; /* Don't use KEYREAD optimization on this table */ tbl->no_keyread=1; /* Don't use record cache */ tbl->no_cache= 1; tbl->covering_keys.clear_all(); if (tbl->file->has_transactions()) transactional_tables= 1; else normal_tables= 1; tbl->prepare_triggers_for_delete_stmt_or_event(); tbl->prepare_for_position(); } else if ((tab->type != JT_SYSTEM && tab->type != JT_CONST) && walk == delete_tables) { /* We are not deleting from the table we are scanning. In this case send_data() shouldn't delete any rows a we may touch the rows in the deleted table many times */ delete_while_scanning= false; } } walk= delete_tables; tempfiles_ptr= tempfiles; if (delete_while_scanning) { table_being_deleted= delete_tables; walk= walk->next_local; } for (;walk ;walk= walk->next_local) { TABLE *table=walk->table; *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); } multi_delete::~multi_delete() { for (table_being_deleted= delete_tables; table_being_deleted; table_being_deleted= table_being_deleted->next_local) { TABLE *table= table_being_deleted->table; table->no_keyread=0; table->no_cache= 0; } for (uint counter= 0; counter < num_of_tables; counter++) { if (tempfiles[counter]) delete tempfiles[counter]; } } int multi_delete::send_data(List &values) { int secure_counter= delete_while_scanning ? -1 : 0; TABLE_LIST *del_table; DBUG_ENTER("multi_delete::send_data"); bool ignore= thd->lex->ignore; for (del_table= delete_tables; del_table; del_table= del_table->next_local, secure_counter++) { TABLE *table= del_table->table; /* Check if we are using outer join and we didn't find the row */ if (table->status & (STATUS_NULL_ROW | STATUS_DELETED)) continue; table->file->position(table->record[0]); found++; if (secure_counter < 0) { /* We are scanning the current table */ DBUG_ASSERT(del_table == table_being_deleted); if (table->triggers && table->triggers->process_triggers(thd, TRG_EVENT_DELETE, TRG_ACTION_BEFORE, FALSE)) DBUG_RETURN(1); table->status|= STATUS_DELETED; error= table->delete_row(); if (likely(!error)) { deleted++; if (!table->file->has_transactions()) thd->transaction.stmt.modified_non_trans_table= TRUE; if (table->triggers && table->triggers->process_triggers(thd, TRG_EVENT_DELETE, TRG_ACTION_AFTER, FALSE)) DBUG_RETURN(1); } else if (!ignore) { /* If the IGNORE option is used errors caused by ha_delete_row don't have to stop the iteration. */ table->file->print_error(error,MYF(0)); DBUG_RETURN(1); } } else { error=tempfiles[secure_counter]->unique_add((char*) table->file->ref); if (unlikely(error)) { error= 1; // Fatal error DBUG_RETURN(1); } } } DBUG_RETURN(0); } void multi_delete::abort_result_set() { DBUG_ENTER("multi_delete::abort_result_set"); /* the error was handled or nothing deleted and no side effects return */ if (error_handled || (!thd->transaction.stmt.modified_non_trans_table && !deleted)) DBUG_VOID_RETURN; /* Something already deleted so we have to invalidate cache */ if (deleted) query_cache_invalidate3(thd, delete_tables, 1); if (thd->transaction.stmt.modified_non_trans_table) thd->transaction.all.modified_non_trans_table= TRUE; thd->transaction.all.m_unsafe_rollback_flags|= (thd->transaction.stmt.m_unsafe_rollback_flags & THD_TRANS::DID_WAIT); /* If rows from the first table only has been deleted and it is transactional, just do rollback. The same if all tables are transactional, regardless of where we are. In all other cases do attempt deletes ... */ if (do_delete && normal_tables && (table_being_deleted != delete_tables || !table_being_deleted->table->file->has_transactions())) { /* We have to execute the recorded do_deletes() and write info into the error log */ error= 1; send_eof(); DBUG_ASSERT(error_handled); DBUG_VOID_RETURN; } if (thd->transaction.stmt.modified_non_trans_table) { /* there is only side effects; to binlog with the error */ if (WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open()) { int errcode= query_error_code(thd, thd->killed == NOT_KILLED); /* possible error of writing binary log is ignored deliberately */ (void) thd->binlog_query(THD::ROW_QUERY_TYPE, thd->query(), thd->query_length(), transactional_tables, FALSE, FALSE, errcode); } } DBUG_VOID_RETURN; } /** Do delete from other tables. @retval 0 ok @retval 1 error @todo Is there any reason not use the normal nested-loops join? If not, and there is no documentation supporting it, this method and callee should be removed and there should be hooks within normal execution. */ int multi_delete::do_deletes() { DBUG_ENTER("do_deletes"); DBUG_ASSERT(do_delete); do_delete= 0; // Mark called if (!found) DBUG_RETURN(0); table_being_deleted= (delete_while_scanning ? delete_tables->next_local : delete_tables); for (uint counter= 0; table_being_deleted; table_being_deleted= table_being_deleted->next_local, counter++) { TABLE *table = table_being_deleted->table; int local_error; if (unlikely(tempfiles[counter]->get(table))) DBUG_RETURN(1); local_error= do_table_deletes(table, &tempfiles[counter]->sort, thd->lex->ignore); if (unlikely(thd->killed) && likely(!local_error)) DBUG_RETURN(1); if (unlikely(local_error == -1)) // End of file local_error= 0; if (unlikely(local_error)) DBUG_RETURN(local_error); } DBUG_RETURN(0); } /** Implements the inner loop of nested-loops join within multi-DELETE execution. @param table The table from which to delete. @param ignore If used, all non fatal errors will be translated to warnings and we should not break the row-by-row iteration. @return Status code @retval 0 All ok. @retval 1 Triggers or handler reported error. @retval -1 End of file from handler. */ int multi_delete::do_table_deletes(TABLE *table, SORT_INFO *sort_info, bool ignore) { int local_error= 0; READ_RECORD info; ha_rows last_deleted= deleted; DBUG_ENTER("do_deletes_for_table"); if (unlikely(init_read_record(&info, thd, table, NULL, sort_info, 0, 1, FALSE))) DBUG_RETURN(1); bool will_batch= !table->file->start_bulk_delete(); while (likely(!(local_error= info.read_record())) && likely(!thd->killed)) { if (table->triggers && unlikely(table->triggers->process_triggers(thd, TRG_EVENT_DELETE, TRG_ACTION_BEFORE, FALSE))) { local_error= 1; break; } local_error= table->delete_row(); if (unlikely(local_error) && !ignore) { table->file->print_error(local_error, MYF(0)); break; } /* Increase the reported number of deleted rows only if no error occurred during ha_delete_row. Also, don't execute the AFTER trigger if the row operation failed. */ if (unlikely(!local_error)) { deleted++; if (table->triggers && table->triggers->process_triggers(thd, TRG_EVENT_DELETE, TRG_ACTION_AFTER, FALSE)) { local_error= 1; break; } } } if (will_batch) { int tmp_error= table->file->end_bulk_delete(); if (unlikely(tmp_error) && !local_error) { local_error= tmp_error; table->file->print_error(local_error, MYF(0)); } } if (last_deleted != deleted && !table->file->has_transactions()) thd->transaction.stmt.modified_non_trans_table= TRUE; end_read_record(&info); DBUG_RETURN(local_error); } /* Send ok to the client return: 0 sucess 1 error */ bool multi_delete::send_eof() { killed_state killed_status= NOT_KILLED; THD_STAGE_INFO(thd, stage_deleting_from_reference_tables); /* Does deletes for the last n - 1 tables, returns 0 if ok */ int local_error= do_deletes(); // returns 0 if success /* compute a total error to know if something failed */ local_error= local_error || error; killed_status= (local_error == 0)? NOT_KILLED : thd->killed; /* reset used flags */ THD_STAGE_INFO(thd, stage_end); if (thd->transaction.stmt.modified_non_trans_table) thd->transaction.all.modified_non_trans_table= TRUE; thd->transaction.all.m_unsafe_rollback_flags|= (thd->transaction.stmt.m_unsafe_rollback_flags & THD_TRANS::DID_WAIT); /* We must invalidate the query cache before binlog writing and ha_autocommit_... */ if (deleted) { query_cache_invalidate3(thd, delete_tables, 1); } if (likely((local_error == 0) || thd->transaction.stmt.modified_non_trans_table)) { if(WSREP_EMULATE_BINLOG(thd) || mysql_bin_log.is_open()) { int errcode= 0; if (likely(local_error == 0)) thd->clear_error(); else errcode= query_error_code(thd, killed_status == NOT_KILLED); thd->thread_specific_used= TRUE; if (unlikely(thd->binlog_query(THD::ROW_QUERY_TYPE, thd->query(), thd->query_length(), transactional_tables, FALSE, FALSE, errcode) > 0) && !normal_tables) { local_error=1; // Log write failed: roll back the SQL statement } } } if (unlikely(local_error != 0)) error_handled= TRUE; // to force early leave from ::abort_result_set() if (likely(!local_error && !thd->lex->analyze_stmt)) { ::my_ok(thd, deleted); } return 0; }