diff options
Diffstat (limited to 'sql')
| -rw-r--r-- | sql/opt_split.cc | 65 |
1 files changed, 38 insertions, 27 deletions
diff --git a/sql/opt_split.cc b/sql/opt_split.cc index 8848c1820df..99082813d7f 100644 --- a/sql/opt_split.cc +++ b/sql/opt_split.cc @@ -246,10 +246,10 @@ public: List<SplM_plan_info> plan_cache; /* Cost of best execution plan for join when nothing is pushed */ double unsplit_cost; + /* Split operation cost (result form spl_postjoin_oper_cost()) */ + double unsplit_oper_cost; /* Cardinality of T when nothing is pushed */ double unsplit_card; - /* Lastly evaluated execution plan for 'join' with pushed equalities */ - SplM_plan_info *last_plan; SplM_plan_info *find_plan(TABLE *table, uint key, uint parts); }; @@ -719,7 +719,6 @@ void JOIN::add_keyuses_for_splitting() size_t idx; KEYUSE_EXT *keyuse_ext; KEYUSE_EXT keyuse_ext_end; - double oper_cost; uint rec_len; uint added_keyuse_count; TABLE *table= select_lex->master_unit()->derived->table; @@ -746,10 +745,11 @@ void JOIN::add_keyuses_for_splitting() rec_len= table->s->rec_buff_length; - oper_cost= spl_postjoin_oper_cost(thd, join_record_count, rec_len); - - spl_opt_info->unsplit_cost= best_positions[table_count-1].read_time + - oper_cost; + spl_opt_info->unsplit_oper_cost= spl_postjoin_oper_cost(thd, + join_record_count, + rec_len); + spl_opt_info->unsplit_cost= (best_positions[table_count-1].read_time + + spl_opt_info->unsplit_oper_cost); if (!(save_qep= new Join_plan_state(table_count + 1))) goto err; @@ -906,6 +906,7 @@ SplM_plan_info * JOIN_TAB::choose_best_splitting(double record_count, SplM_plan_info *spl_plan= 0; uint best_key= 0; uint best_key_parts= 0; + bool chosen, already_printed; /* Check whether there are keys that can be used to join T employing splitting @@ -963,7 +964,7 @@ SplM_plan_info * JOIN_TAB::choose_best_splitting(double record_count, } while (keyuse_ext->table == table); } - spl_opt_info->last_plan= 0; + chosen= 0; if (best_table) { /* @@ -1018,49 +1019,58 @@ SplM_plan_info * JOIN_TAB::choose_best_splitting(double record_count, spl_plan->cost= (join->best_positions[join->table_count-1].read_time + oper_cost); + chosen= (record_count * spl_plan->cost + COST_EPS < + spl_opt_info->unsplit_cost); + if (unlikely(thd->trace_started())) { Json_writer_object wrapper(thd); - Json_writer_object find_trace(thd, "best_splitting"); + Json_writer_object find_trace(thd, "split_materialized"); find_trace. add("table", best_table->alias.c_ptr()). add("key", best_table->key_info[best_key].name). - add("record_count", record_count). - add("cost", spl_plan->cost). - add("unsplit_cost", spl_opt_info->unsplit_cost); + add("org_cost",join->best_positions[join->table_count-1].read_time). + add("postjoin_cost", oper_cost). + add("one_splitting_cost", spl_plan->cost). + add("unsplit_postjoin_cost", spl_opt_info->unsplit_oper_cost). + add("unsplit_cost", spl_opt_info->unsplit_cost). + add("rows", split_card). + add("outer_rows", record_count). + add("total_splitting_cost", record_count * spl_plan->cost). + add("chosen", chosen); } memcpy((char *) spl_plan->best_positions, (char *) join->best_positions, sizeof(POSITION) * join->table_count); reset_validity_vars_for_keyuses(best_key_keyuse_ext_start, best_table, best_key, remaining_tables, false); + already_printed= 1; } - if (spl_plan) + else { - if (record_count * spl_plan->cost + COST_EPS < spl_opt_info->unsplit_cost) - { - /* - The best plan that employs splitting is cheaper than - the plan without splitting - */ - spl_opt_info->last_plan= spl_plan; - } + chosen= (record_count * spl_plan->cost + COST_EPS < + spl_opt_info->unsplit_cost); + already_printed= 0; } } /* Set the cost of the preferred materialization for this partial join */ - spl_plan= spl_opt_info->last_plan; - if (spl_plan) + if (chosen) { + /* + The best plan that employs splitting is cheaper than + the plan without splitting + */ + startup_cost= record_count * spl_plan->cost; records= (ha_rows) (spl_opt_info->unsplit_card * spl_plan->split_sel); - if (unlikely(thd->trace_started())) + if (unlikely(thd->trace_started()) && ! already_printed) { - Json_writer_object trace(thd, "lateral_derived"); + Json_writer_object trace(thd, "split_materialized"); trace. - add("startup_cost", startup_cost). - add("splitting_cost", spl_plan->cost). + add("one_splitting_cost", spl_plan->cost). + add("total_splitting_cost", startup_cost). add("rows", records); } } @@ -1069,6 +1079,7 @@ SplM_plan_info * JOIN_TAB::choose_best_splitting(double record_count, /* Restore original values */ startup_cost= spl_opt_info->unsplit_cost; records= (ha_rows) spl_opt_info->unsplit_card; + spl_plan= 0; } return spl_plan; } |