diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 1bf8addbcf0..72c1e876359 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -1447,6 +1447,7 @@ JOIN::optimize_inner() zero_result_cause= "Zero limit"; } table_count= top_join_tab_count= 0; + handle_implicit_grouping_with_window_funcs(); error= 0; goto setup_subq_exit; } @@ -1502,6 +1503,7 @@ JOIN::optimize_inner() zero_result_cause= "No matching min/max row"; table_count= top_join_tab_count= 0; error=0; + handle_implicit_grouping_with_window_funcs(); goto setup_subq_exit; } if (res > 1) @@ -1517,6 +1519,7 @@ 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 @@ -1615,6 +1618,7 @@ JOIN::optimize_inner() 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) && @@ -1639,6 +1643,7 @@ JOIN::optimize_inner() 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; } @@ -1781,6 +1786,7 @@ JOIN::optimize_inner() 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; } @@ -18225,7 +18231,8 @@ 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); @@ -26925,6 +26932,28 @@ 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) */ |