diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 77 |
1 files changed, 71 insertions, 6 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 2c7ccbf3e2b..e8e399868db 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -1451,6 +1451,7 @@ JOIN::optimize_inner() if (!select_lex->have_window_funcs()) zero_result_cause= "Select tables optimized away"; tables_list= 0; // All tables resolved + select_lex->min_max_opt_list.empty(); const_tables= top_join_tab_count= table_count; /* Extract all table-independent conditions and replace the WHERE @@ -2662,8 +2663,11 @@ bool JOIN::make_aggr_tables_info() if (sort_table_cond) { if (!curr_tab->select) + { if (!(curr_tab->select= new SQL_SELECT)) DBUG_RETURN(true); + curr_tab->select->head= curr_tab->table; + } if (!curr_tab->select->cond) curr_tab->select->cond= sort_table_cond; else @@ -5971,7 +5975,7 @@ add_group_and_distinct_keys(JOIN *join, JOIN_TAB *join_tab) Item_field *cur_item; key_map possible_keys(0); - if (join->group_list) + if (join->group_list || join->simple_group) { /* Collect all query fields referenced in the GROUP clause. */ for (cur_group= join->group_list; cur_group; cur_group= cur_group->next) (*cur_group->item)->walk(&Item::collect_item_field_processor, 0, @@ -8367,6 +8371,63 @@ bool JOIN_TAB::hash_join_is_possible() } +/** + @brief + Check whether a KEYUSE can be really used for access this join table + + @param join Join structure with the best join order + for which the check is performed + @param keyuse Evaluated KEYUSE structure + + @details + This function is supposed to be used after the best execution plan have been + already chosen and the JOIN_TAB array for the best join order been already set. + For a given KEYUSE to access this JOIN_TAB in the best execution plan the + function checks whether it really can be used. The function first performs + the check with access_from_tables_is_allowed(). If it succeeds it checks + whether the keyuse->val does not use some fields of a materialized semijoin + nest that cannot be used to build keys to access outer tables. + Such KEYUSEs exists for the query like this: + select * from ot + where ot.c in (select it1.c from it1, it2 where it1.c=f(it2.c)) + Here we have two KEYUSEs to access table ot: with val=it1.c and val=f(it2.c). + However if the subquery was materialized the second KEYUSE cannot be employed + to access ot. + + @retval true the given keyuse can be used for ref access of this JOIN_TAB + @retval false otherwise +*/ + +bool JOIN_TAB::keyuse_is_valid_for_access_in_chosen_plan(JOIN *join, + KEYUSE *keyuse) +{ + if (!access_from_tables_is_allowed(keyuse->used_tables, + join->sjm_lookup_tables)) + return false; + if (join->sjm_scan_tables & table->map) + return true; + table_map keyuse_sjm_scan_tables= keyuse->used_tables & + join->sjm_scan_tables; + if (!keyuse_sjm_scan_tables) + return true; + uint sjm_tab_nr= 0; + while (!(keyuse_sjm_scan_tables & table_map(1) << sjm_tab_nr)) + sjm_tab_nr++; + JOIN_TAB *sjm_tab= join->map2table[sjm_tab_nr]; + TABLE_LIST *emb_sj_nest= sjm_tab->emb_sj_nest; + if (!(emb_sj_nest->sj_mat_info && emb_sj_nest->sj_mat_info->is_used && + emb_sj_nest->sj_mat_info->is_sj_scan)) + return true; + st_select_lex *sjm_sel= emb_sj_nest->sj_subq_pred->unit->first_select(); + for (uint i= 0; i < sjm_sel->item_list.elements; i++) + { + if (sjm_sel->ref_pointer_array[i] == keyuse->val) + return true; + } + return false; +} + + static uint cache_record_length(JOIN *join,uint idx) { @@ -8956,6 +9017,7 @@ static bool create_hj_key_for_table(JOIN *join, JOIN_TAB *join_tab, do { if (!(~used_tables & keyuse->used_tables) && + join_tab->keyuse_is_valid_for_access_in_chosen_plan(join, keyuse) && are_tables_local(join_tab, keyuse->used_tables)) { if (first_keyuse) @@ -8970,6 +9032,8 @@ static bool create_hj_key_for_table(JOIN *join, JOIN_TAB *join_tab, { if (curr->keypart == keyuse->keypart && !(~used_tables & curr->used_tables) && + join_tab->keyuse_is_valid_for_access_in_chosen_plan(join, + keyuse) && are_tables_local(join_tab, curr->used_tables)) break; } @@ -9004,6 +9068,7 @@ static bool create_hj_key_for_table(JOIN *join, JOIN_TAB *join_tab, do { if (!(~used_tables & keyuse->used_tables) && + join_tab->keyuse_is_valid_for_access_in_chosen_plan(join, keyuse) && are_tables_local(join_tab, keyuse->used_tables)) { bool add_key_part= TRUE; @@ -9013,7 +9078,9 @@ static bool create_hj_key_for_table(JOIN *join, JOIN_TAB *join_tab, { if (curr->keypart == keyuse->keypart && !(~used_tables & curr->used_tables) && - are_tables_local(join_tab, curr->used_tables)) + join_tab->keyuse_is_valid_for_access_in_chosen_plan(join, + curr) && + are_tables_local(join_tab, curr->used_tables)) { keyuse->keypart= NO_KEYPART; add_key_part= FALSE; @@ -9115,8 +9182,7 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j, do { if (!(~used_tables & keyuse->used_tables) && - j->access_from_tables_is_allowed(keyuse->used_tables, - join->sjm_lookup_tables)) + j->keyuse_is_valid_for_access_in_chosen_plan(join, keyuse)) { if (are_tables_local(j, keyuse->val->used_tables())) { @@ -9186,8 +9252,7 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j, for (i=0 ; i < keyparts ; keyuse++,i++) { while (((~used_tables) & keyuse->used_tables) || - !j->access_from_tables_is_allowed(keyuse->used_tables, - join->sjm_lookup_tables) || + !j->keyuse_is_valid_for_access_in_chosen_plan(join, keyuse) || keyuse->keypart == NO_KEYPART || (keyuse->keypart != (is_hash_join_key_no(key) ? |