diff options
Diffstat (limited to 'sql/opt_subselect.cc')
| -rw-r--r-- | sql/opt_subselect.cc | 66 |
1 files changed, 54 insertions, 12 deletions
diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc index d06480391be..4559b76764e 100644 --- a/sql/opt_subselect.cc +++ b/sql/opt_subselect.cc @@ -251,8 +251,8 @@ bool is_materialization_applicable(THD *thd, Item_in_subselect *in_subs, Subquery !contains {GROUP BY, ORDER BY [LIMIT], aggregate functions}) && subquery predicate is not under "NOT IN")) - (*) The subquery must be part of a SELECT statement. The current - condition also excludes multi-table update statements. + (*) The subquery must be part of a SELECT or CREATE TABLE ... SELECT statement. + The current condition also excludes multi-table update statements. A note about prepared statements: we want the if-branch to be taken on PREPARE and each EXECUTE. The rewrites are only done once, but we need select_lex->sj_subselects list to be populated for every EXECUTE. @@ -261,7 +261,8 @@ bool is_materialization_applicable(THD *thd, Item_in_subselect *in_subs, if (optimizer_flag(thd, OPTIMIZER_SWITCH_MATERIALIZATION) && // 0 !child_select->is_part_of_union() && // 1 parent_unit->first_select()->leaf_tables.elements && // 2 - thd->lex->sql_command == SQLCOM_SELECT && // * + (thd->lex->sql_command == SQLCOM_SELECT || // * + thd->lex->sql_command == SQLCOM_CREATE_TABLE) && // * child_select->outer_select()->leaf_tables.elements && // 2A subquery_types_allow_materialization(in_subs) && (in_subs->is_top_level_item() || //3 @@ -597,7 +598,7 @@ bool subquery_types_allow_materialization(Item_in_subselect *in_subs) break; case TIME_RESULT: if (mysql_type_to_time_type(outer->field_type()) != - mysql_type_to_time_type(outer->field_type())) + mysql_type_to_time_type(inner->field_type())) DBUG_RETURN(FALSE); default: /* suitable for materialization */ @@ -3167,6 +3168,7 @@ bool setup_sj_materialization_part1(JOIN_TAB *sjm_tab) sjm->sjm_table_cols.push_back(*p_item); sjm->sjm_table_param.field_count= subq_select->item_list.elements; + sjm->sjm_table_param.force_not_null_cols= TRUE; if (!(sjm->table= create_tmp_table(thd, &sjm->sjm_table_param, sjm->sjm_table_cols, (ORDER*) 0, @@ -4079,7 +4081,8 @@ int setup_semijoin_dups_elimination(JOIN *join, ulonglong options, { uint i; DBUG_ENTER("setup_semijoin_dups_elimination"); - + + join->complex_firstmatch_tables= table_map(0); POSITION *pos= join->best_positions + join->const_tables; for (i= join->const_tables ; i < join->top_join_tab_count; ) @@ -4098,6 +4101,11 @@ int setup_semijoin_dups_elimination(JOIN *join, ulonglong options, { /* We jump from the last table to the first one */ tab->loosescan_match_tab= tab + pos->n_sj_tables - 1; + + /* LooseScan requires records to be produced in order */ + if (tab->select && tab->select->quick) + tab->select->quick->need_sorted_output(); + for (uint j= i; j < i + pos->n_sj_tables; j++) join->join_tab[j].inside_loosescan_range= TRUE; @@ -4107,6 +4115,7 @@ int setup_semijoin_dups_elimination(JOIN *join, ulonglong options, for (uint kp=0; kp < pos->loosescan_picker.loosescan_parts; kp++) keylen += tab->table->key_info[keyno].key_part[kp].store_length; + tab->loosescan_key= keyno; tab->loosescan_key_len= keylen; if (pos->n_sj_tables > 1) tab[pos->n_sj_tables - 1].do_firstmatch= tab; @@ -4162,16 +4171,46 @@ int setup_semijoin_dups_elimination(JOIN *join, ulonglong options, } case SJ_OPT_FIRST_MATCH: { - JOIN_TAB *j, *jump_to= tab-1; + JOIN_TAB *j; + JOIN_TAB *jump_to= tab-1; + + bool complex_range= FALSE; + table_map tables_in_range= table_map(0); + for (j= tab; j != tab + pos->n_sj_tables; j++) { - /* - NOTE: this loop probably doesn't do the right thing for the case - where FirstMatch's duplicate-generating range is interleaved with - "unrelated" tables (as specified in WL#3750, section 2.2). - */ + tables_in_range |= j->table->map; if (!j->emb_sj_nest) - jump_to= tab; + { + /* + Got a table that's not within any semi-join nest. This is a case + like this: + + SELECT * FROM ot1, nt1 WHERE ot1.col IN (SELECT expr FROM it1, it2) + + with a join order of + + +----- FirstMatch range ----+ + | | + ot1 it1 nt1 nt2 it2 it3 ... + | ^ + | +-------- 'j' points here + +------------- SJ_OPT_FIRST_MATCH was set for this table as + it's the first one that produces duplicates + + */ + DBUG_ASSERT(j != tab); /* table ntX must have an itX before it */ + + /* + If the table right before us is an inner table (like it1 in the + picture), it should be set to jump back to previous outer-table + */ + if (j[-1].emb_sj_nest) + j[-1].do_firstmatch= jump_to; + + jump_to= j; /* Jump back to us */ + complex_range= TRUE; + } else { j->first_sj_inner_tab= tab; @@ -4181,6 +4220,9 @@ int setup_semijoin_dups_elimination(JOIN *join, ulonglong options, j[-1].do_firstmatch= jump_to; i+= pos->n_sj_tables; pos+= pos->n_sj_tables; + + if (complex_range) + join->complex_firstmatch_tables|= tables_in_range; break; } case SJ_OPT_NONE: |