diff options
| -rw-r--r-- | mysql-test/r/selectivity.result | 34 | ||||
| -rw-r--r-- | mysql-test/r/selectivity_innodb.result | 34 | ||||
| -rw-r--r-- | mysql-test/t/selectivity.test | 27 | ||||
| -rw-r--r-- | sql/sql_statistics.cc | 9 | ||||
| -rw-r--r-- | sql/sql_statistics.h | 11 |
5 files changed, 111 insertions, 4 deletions
diff --git a/mysql-test/r/selectivity.result b/mysql-test/r/selectivity.result index 4d45d6b175b..0f519c53f3e 100644 --- a/mysql-test/r/selectivity.result +++ b/mysql-test/r/selectivity.result @@ -1910,5 +1910,39 @@ HEX(a) b set optimizer_use_condition_selectivity= @save_optimizer_use_condition_selectivity; set histogram_size=@save_histogram_size; DROP TABLE t1; +# +# MDEV-19474: Histogram statistics are used even with optimizer_use_condition_selectivity=3 +# +CREATE TABLE t1(a int); +INSERT INTO t1 values (1),(2),(2),(3),(4); +SET optimizer_use_condition_selectivity=4; +SET histogram_size= 255; +set use_stat_tables='preferably'; +ANALYZE TABLE t1 PERSISTENT FOR ALL; +Table Op Msg_type Msg_text +test.t1 analyze status Engine-independent statistics collected +test.t1 analyze status OK +EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 5 39.84 Using where +Warnings: +Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 2 +SET optimizer_use_condition_selectivity=3; +# filtered should show 25 % +EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 5 25.00 Using where +Warnings: +Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 2 +FLUSH TABLES; +EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 5 25.00 Using where +Warnings: +Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 2 +set optimizer_use_condition_selectivity= @save_optimizer_use_condition_selectivity; +set histogram_size=@save_histogram_size; +set use_stat_tables= @save_use_stat_tables; +DROP TABLE t1; # End of 10.2 tests set @@global.histogram_size=@save_histogram_size; diff --git a/mysql-test/r/selectivity_innodb.result b/mysql-test/r/selectivity_innodb.result index b97bbf8153f..5452919aa6d 100644 --- a/mysql-test/r/selectivity_innodb.result +++ b/mysql-test/r/selectivity_innodb.result @@ -1920,6 +1920,40 @@ HEX(a) b set optimizer_use_condition_selectivity= @save_optimizer_use_condition_selectivity; set histogram_size=@save_histogram_size; DROP TABLE t1; +# +# MDEV-19474: Histogram statistics are used even with optimizer_use_condition_selectivity=3 +# +CREATE TABLE t1(a int); +INSERT INTO t1 values (1),(2),(2),(3),(4); +SET optimizer_use_condition_selectivity=4; +SET histogram_size= 255; +set use_stat_tables='preferably'; +ANALYZE TABLE t1 PERSISTENT FOR ALL; +Table Op Msg_type Msg_text +test.t1 analyze status Engine-independent statistics collected +test.t1 analyze status OK +EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 5 39.84 Using where +Warnings: +Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 2 +SET optimizer_use_condition_selectivity=3; +# filtered should show 25 % +EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 5 25.00 Using where +Warnings: +Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 2 +FLUSH TABLES; +EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2; +id select_type table type possible_keys key key_len ref rows filtered Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 5 25.00 Using where +Warnings: +Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 2 +set optimizer_use_condition_selectivity= @save_optimizer_use_condition_selectivity; +set histogram_size=@save_histogram_size; +set use_stat_tables= @save_use_stat_tables; +DROP TABLE t1; # End of 10.2 tests set @@global.histogram_size=@save_histogram_size; set optimizer_switch=@save_optimizer_switch_for_selectivity_test; diff --git a/mysql-test/t/selectivity.test b/mysql-test/t/selectivity.test index b4f535f1584..4d7dcdc9781 100644 --- a/mysql-test/t/selectivity.test +++ b/mysql-test/t/selectivity.test @@ -1302,6 +1302,33 @@ set optimizer_use_condition_selectivity= @save_optimizer_use_condition_selectivi set histogram_size=@save_histogram_size; DROP TABLE t1; +--echo # +--echo # MDEV-19474: Histogram statistics are used even with optimizer_use_condition_selectivity=3 +--echo # + +CREATE TABLE t1(a int); +INSERT INTO t1 values (1),(2),(2),(3),(4); +SET optimizer_use_condition_selectivity=4; +SET histogram_size= 255; + +set use_stat_tables='preferably'; + +ANALYZE TABLE t1 PERSISTENT FOR ALL; + +EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2; +SET optimizer_use_condition_selectivity=3; + +--echo # filtered should show 25 % +EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2; +FLUSH TABLES; + +EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=2; +set optimizer_use_condition_selectivity= @save_optimizer_use_condition_selectivity; +set histogram_size=@save_histogram_size; +set use_stat_tables= @save_use_stat_tables; + +DROP TABLE t1; + --echo # End of 10.2 tests # diff --git a/sql/sql_statistics.cc b/sql/sql_statistics.cc index 39fcfd7e6db..f2aa8b8063e 100644 --- a/sql/sql_statistics.cc +++ b/sql/sql_statistics.cc @@ -3732,6 +3732,7 @@ double get_column_range_cardinality(Field *field, if (!table->stats_is_read) return tab_records; + THD *thd= table->in_use; double col_nulls= tab_records * col_stats->get_nulls_ratio(); double col_non_nulls= tab_records - col_nulls; @@ -3762,7 +3763,7 @@ double get_column_range_cardinality(Field *field, col_stats->min_max_values_are_provided()) { Histogram *hist= &col_stats->histogram; - if (hist->is_available()) + if (hist->is_usable(thd)) { store_key_image_to_rec(field, (uchar *) min_endp->key, field->key_length()); @@ -3806,10 +3807,10 @@ double get_column_range_cardinality(Field *field, max_mp_pos= 1.0; Histogram *hist= &col_stats->histogram; - if (!hist->is_available()) - sel= (max_mp_pos - min_mp_pos); - else + if (hist->is_usable(thd)) sel= hist->range_selectivity(min_mp_pos, max_mp_pos); + else + sel= (max_mp_pos - min_mp_pos); res= col_non_nulls * sel; set_if_bigger(res, col_stats->get_avg_frequency()); } diff --git a/sql/sql_statistics.h b/sql/sql_statistics.h index fa3e8d6b894..d8788d99574 100644 --- a/sql/sql_statistics.h +++ b/sql/sql_statistics.h @@ -212,6 +212,17 @@ public: bool is_available() { return get_size() > 0 && get_values(); } + /* + This function checks that histograms should be usable only when + 1) the level of optimizer_use_condition_selectivity > 3 + 2) histograms have been collected + */ + bool is_usable(THD *thd) + { + return thd->variables.optimizer_use_condition_selectivity > 3 && + is_available(); + } + void set_value(uint i, double val) { switch (type) { |