diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 36 |
1 files changed, 33 insertions, 3 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 275c46141cd..da8dfdd015a 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -1812,6 +1812,7 @@ JOIN::optimize_inner() zero_result_cause= "Zero limit"; } table_count= top_join_tab_count= 0; + handle_implicit_grouping_with_window_funcs(); error= 0; subq_exit_fl= true; goto setup_subq_exit; @@ -1859,6 +1860,7 @@ JOIN::optimize_inner() table_count= top_join_tab_count= 0; error=0; subq_exit_fl= true; + handle_implicit_grouping_with_window_funcs(); goto setup_subq_exit; } if (res > 1) @@ -1874,6 +1876,7 @@ JOIN::optimize_inner() tables_list= 0; // All tables resolved select_lex->min_max_opt_list.empty(); const_tables= top_join_tab_count= table_count; + handle_implicit_grouping_with_window_funcs(); /* Extract all table-independent conditions and replace the WHERE clause with them. All other conditions were computed by opt_sum_query @@ -2019,6 +2022,7 @@ int JOIN::optimize_stage2() zero_result_cause= "no matching row in const table"; DBUG_PRINT("error",("Error: %s", zero_result_cause)); error= 0; + handle_implicit_grouping_with_window_funcs(); goto setup_subq_exit; } if (!(thd->variables.option_bits & OPTION_BIG_SELECTS) && @@ -2050,6 +2054,7 @@ int JOIN::optimize_stage2() zero_result_cause= "Impossible WHERE noticed after reading const tables"; select_lex->mark_const_derived(zero_result_cause); + handle_implicit_grouping_with_window_funcs(); goto setup_subq_exit; } @@ -2195,6 +2200,7 @@ int JOIN::optimize_stage2() zero_result_cause= "Impossible WHERE noticed after reading const tables"; select_lex->mark_const_derived(zero_result_cause); + handle_implicit_grouping_with_window_funcs(); goto setup_subq_exit; } @@ -15024,7 +15030,7 @@ static COND* substitute_for_best_equal_field(THD *thd, JOIN_TAB *context_tab, } } else if (cond->type() == Item::FUNC_ITEM && - ((Item_cond*) cond)->functype() == Item_func::MULT_EQUAL_FUNC) + ((Item_func*) cond)->functype() == Item_func::MULT_EQUAL_FUNC) { item_equal= (Item_equal *) cond; item_equal->sort(&compare_fields_by_table_order, table_join_idx); @@ -18946,7 +18952,8 @@ void set_postjoin_aggr_write_func(JOIN_TAB *tab) } } else if (join->sort_and_group && !tmp_tbl->precomputed_group_by && - !join->sort_and_group_aggr_tab && join->tables_list) + !join->sort_and_group_aggr_tab && join->tables_list && + join->top_join_tab_count) { DBUG_PRINT("info",("Using end_write_group")); aggr->set_write_func(end_write_group); @@ -24359,7 +24366,8 @@ change_to_use_tmp_fields(THD *thd, Ref_ptr_array ref_pointer_array, for (uint i= 0; (item= it++); i++) { Field *field; - if (item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM) + if ((item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM) || + item->with_window_func) item_field= item; else if (item->type() == Item::FIELD_ITEM) { @@ -27751,6 +27759,28 @@ Item *remove_pushed_top_conjuncts(THD *thd, Item *cond) return cond; } +/* + There are 5 cases in which we shortcut the join optimization process as we + conclude that the join would be a degenerate one + 1) IMPOSSIBLE WHERE + 2) MIN/MAX optimization (@see opt_sum_query) + 3) EMPTY CONST TABLE + If a window function is present in any of the above cases then to get the + result of the window function, we need to execute it. So we need to + create a temporary table for its execution. Here we need to take in mind + that aggregate functions and non-aggregate function need not be executed. + +*/ + + +void JOIN::handle_implicit_grouping_with_window_funcs() +{ + if (select_lex->have_window_funcs() && send_row_on_empty_set()) + { + const_tables= top_join_tab_count= table_count= 0; + } +} + /** @} (end of group Query_Optimizer) */ |