diff options
Diffstat (limited to 'sql/opt_subselect.cc')
| -rw-r--r-- | sql/opt_subselect.cc | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc index 9c8fc6dc0b3..1bdbcf0deb9 100644 --- a/sql/opt_subselect.cc +++ b/sql/opt_subselect.cc @@ -4148,6 +4148,7 @@ void fix_semijoin_strategies_for_picked_join_order(JOIN *join) */ join->cur_sj_inner_tables= 0; Json_writer_object semijoin_strategy(thd); + double inner_fanout= 1.0; semijoin_strategy.add("semi_join_strategy","FirstMatch"); Json_writer_array semijoin_plan(thd, "join_order"); for (idx= first; idx <= tablenr; idx++) @@ -4165,10 +4166,22 @@ void fix_semijoin_strategies_for_picked_join_order(JOIN *join) TRUE /* no jbuf */, record_count, join->best_positions + idx, &dummy); } + /* + TODO: We should also compute the selectivity here, as well as adjust + the records_out according to the fraction of records removed by + the semi-join. + */ + double rec_out= join->best_positions[idx].records_out; + if (join->best_positions[idx].table->emb_sj_nest) + inner_fanout *= rec_out; + record_count *= join->best_positions[idx].records_out; rem_tables &= ~join->best_positions[idx].table->table->map; } + if (inner_fanout > 1.0) + join->best_positions[tablenr].records_out /= inner_fanout; } + if (pos->sj_strategy == SJ_OPT_LOOSE_SCAN) { @@ -4947,11 +4960,13 @@ SJ_TMP_TABLE::create_sj_weedout_tmp_table(THD *thd) { DBUG_PRINT("info",("Creating group key in temporary table")); share->keys=1; - share->uniques= MY_TEST(using_unique_constraint); table->key_info= share->key_info= keyinfo; keyinfo->key_part=key_part_info; - keyinfo->flags=HA_NOSAME; + keyinfo->flags= HA_NOSAME | (using_unique_constraint ? HA_UNIQUE_HASH : 0); + keyinfo->ext_key_flags= keyinfo->flags; keyinfo->usable_key_parts= keyinfo->user_defined_key_parts= 1; + keyinfo->ext_key_parts= 1; + share->key_parts= 1; keyinfo->key_length=0; keyinfo->rec_per_key=0; keyinfo->algorithm= HA_KEY_ALG_UNDEF; |