diff options
Diffstat (limited to 'sql/opt_subselect.cc')
| -rw-r--r-- | sql/opt_subselect.cc | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc index 9e92231d519..53fbefb3795 100644 --- a/sql/opt_subselect.cc +++ b/sql/opt_subselect.cc @@ -1455,8 +1455,8 @@ void get_delayed_table_estimates(TABLE *table, hash_sj_engine->tmp_table->s->reclength); /* Do like in handler::ha_scan_and_compare_time, but ignore the where cost */ - *scan_time= ((data_size/table->file->stats.block_size+2) * - table->file->avg_io_cost()) + *out_rows * file->ROW_COPY_COST; + *scan_time= ((data_size/IO_SIZE * table->file->avg_io_cost()) + + *out_rows * file->ROW_COPY_COST); } @@ -2573,19 +2573,17 @@ bool optimize_semijoin_nests(JOIN *join, table_map all_table_map) consider doing sjm-scan). See ha_scan_time() for the basics of the calculations. We don't need to check the where clause for each row, so no - WHERE_COMPARE_COST is needed. + WHERE_COST is needed. */ - scan_cost= (TABLE_SCAN_SETUP_COST + - (cost.block_size == 0 ? 0 : - ((rowlen * (double) sjm->rows) / cost.block_size + - TABLE_SCAN_SETUP_COST))); + scan_cost= (rowlen * (double) sjm->rows) / cost.block_size; total_cost= (scan_cost * cost.cache_hit_ratio * cost.avg_io_cost + + TABLE_SCAN_SETUP_COST + row_copy_cost * sjm->rows); sjm->scan_cost.convert_from_cost(total_cost); /* When reading a row, we have also to check the where clause */ sjm->lookup_cost.convert_from_cost(cost.lookup + - WHERE_COMPARE_COST_THD(thd)); + WHERE_COST_THD(thd)); sj_nest->sj_mat_info= sjm; DBUG_EXECUTE("opt", print_sjm(sjm);); } @@ -2690,8 +2688,12 @@ get_tmp_table_costs(THD *thd, double row_count, uint row_size, bool blobs_used, blobs_used) { /* Disk based table */ - cost.lookup= ((DISK_TEMPTABLE_LOOKUP_COST * + cost.lookup= ((DISK_TEMPTABLE_LOOKUP_COST(thd) * thd->optimizer_cache_hit_ratio)) + row_copy_cost; + /* + On write we have to first copy the row to the record buffer and then + to the storage engine, so 2 copies. + */ cost.write= cost.lookup + row_copy_cost; cost.create= DISK_TEMPTABLE_CREATE_COST; cost.block_size= DISK_TEMPTABLE_BLOCK_SIZE; @@ -2704,8 +2706,8 @@ get_tmp_table_costs(THD *thd, double row_count, uint row_size, bool blobs_used, cost.lookup= HEAP_TEMPTABLE_LOOKUP_COST + row_copy_cost; cost.write= cost.lookup + row_copy_cost; cost.create= HEAP_TEMPTABLE_CREATE_COST; - cost.block_size= 0; - cost.avg_io_cost= HEAP_TEMPTABLE_LOOKUP_COST; + cost.block_size= 1; + cost.avg_io_cost= 0; cost.cache_hit_ratio= 1.0; } return cost; @@ -6731,7 +6733,7 @@ bool JOIN::choose_subquery_plan(table_map join_tables) double materialization_cost= COST_ADD(cost.create, COST_ADD(inner_read_time_1, - COST_MULT((cost.write + WHERE_COMPARE_COST_THD(thd)), + COST_MULT((cost.write + WHERE_COST_THD(thd)), inner_record_count_1))); materialize_strategy_cost= |