revision-id: d4aae0b47b396a142fd413ff5f5ac5df1ff3c560 (mariadb-10.3.31-70-gd4aae0b47b3) parent(s): 9962cda52722b77c2a7e0314bbaa2e4f963f55c1 author: Sergei Petrunia committer: Sergei Petrunia timestamp: 2022-01-04 00:01:52 +0300 message: MDEV-26337: subquery with groupby and ROLLUP returns incorrect results on LEFT JOIN on INDEXED values Disable LATERAL DERIVED optimization for subqueries that have WITH ROLLUP. --- mysql-test/main/derived_split_innodb.result | 42 +++++++++++++++++++++++++++++ mysql-test/main/derived_split_innodb.test | 36 +++++++++++++++++++++++++ sql/opt_split.cc | 5 +++- 3 files changed, 82 insertions(+), 1 deletion(-) diff --git a/mysql-test/main/derived_split_innodb.result b/mysql-test/main/derived_split_innodb.result index 7ea3b689f23..8162bfcdae7 100644 --- a/mysql-test/main/derived_split_innodb.result +++ b/mysql-test/main/derived_split_innodb.result @@ -234,4 +234,46 @@ id itemid id id 4 2 4 2 drop table t1,t2,t3; set optimizer_switch='split_materialized=default'; +# +# MDEV-26337: subquery with groupby and ROLLUP returns incorrect results +# (The testcase is taken from testcase for MDEV-13389 due to it being +# much smaller) +# +create table t3 (a int, b int, c char(127), index idx_b(b)) engine=myisam; +insert into t3 values +(8,11,'aa'), (5,15,'cc'), (1,14,'bb'), (2,12,'aa'), (7,17,'cc'), +(7,18,'aa'), (2,11,'aa'), (7,10,'bb'), (3,11,'dd'), (4,12,'ee'), +(5,14,'dd'), (9,12,'ee'); +create table t4 (a int, b int, c char(127), index idx(a,c)) engine=myisam; +insert into t4 values +(7,10,'cc'), (1,20,'aa'), (2,23,'bb'), (7,18,'cc'), (1,30,'bb'), +(4,71,'xx'), (3,15,'aa'), (7,82,'aa'), (8,12,'dd'), (4,15,'aa'), +(11,33,'yy'), (10,42,'zz'), (4,53,'xx'), (10,17,'yy'), (7,12,'cc'), +(8,20,'dd'), (7,32,'bb'), (1,50,'aa'), (3,40,'bb'), (3,77,'aa'); +insert into t4 select a+10, b+10, concat(c,'f') from t4; +analyze table t3,t4; +Table Op Msg_type Msg_text +test.t3 analyze status OK +test.t4 analyze status OK +# This should use a plan with LATERAL DERIVED: +explain select t3.a,t3.c,t.max,t.min +from t3 join +(select a, c, max(b) max, min(b) min from t4 group by a,c) t +on t3.a=t.a and t3.c=t.c +where t3.b > 15; +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY t3 range idx_b idx_b 5 NULL 3 Using index condition; Using where +1 PRIMARY <derived2> ref key0 key0 133 test.t3.a,test.t3.c 2 +2 LATERAL DERIVED t4 ref idx idx 133 test.t3.a,test.t3.c 1 +# ... and if one adds WITH ROLLUP, then LATERAL DERIVED is no longer used: +explain select t3.a,t3.c,t.max,t.min +from t3 join +(select a, c, max(b) max, min(b) min from t4 group by a,c with rollup) t +on t3.a=t.a and t3.c=t.c +where t3.b > 15; +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY t3 range idx_b idx_b 5 NULL 3 Using index condition; Using where +1 PRIMARY <derived2> ref key0 key0 133 test.t3.a,test.t3.c 4 +2 DERIVED t4 ALL NULL NULL NULL NULL 40 Using filesort +drop table t3, t4; # End of 10.3 tests diff --git a/mysql-test/main/derived_split_innodb.test b/mysql-test/main/derived_split_innodb.test index 6f33c71eede..2a3565be36f 100644 --- a/mysql-test/main/derived_split_innodb.test +++ b/mysql-test/main/derived_split_innodb.test @@ -186,4 +186,40 @@ eval $q; drop table t1,t2,t3; set optimizer_switch='split_materialized=default'; +--echo # +--echo # MDEV-26337: subquery with groupby and ROLLUP returns incorrect results +--echo # (The testcase is taken from testcase for MDEV-13389 due to it being +--echo # much smaller) +--echo # + +create table t3 (a int, b int, c char(127), index idx_b(b)) engine=myisam; +insert into t3 values +(8,11,'aa'), (5,15,'cc'), (1,14,'bb'), (2,12,'aa'), (7,17,'cc'), +(7,18,'aa'), (2,11,'aa'), (7,10,'bb'), (3,11,'dd'), (4,12,'ee'), +(5,14,'dd'), (9,12,'ee'); +create table t4 (a int, b int, c char(127), index idx(a,c)) engine=myisam; +insert into t4 values +(7,10,'cc'), (1,20,'aa'), (2,23,'bb'), (7,18,'cc'), (1,30,'bb'), +(4,71,'xx'), (3,15,'aa'), (7,82,'aa'), (8,12,'dd'), (4,15,'aa'), +(11,33,'yy'), (10,42,'zz'), (4,53,'xx'), (10,17,'yy'), (7,12,'cc'), +(8,20,'dd'), (7,32,'bb'), (1,50,'aa'), (3,40,'bb'), (3,77,'aa'); +insert into t4 select a+10, b+10, concat(c,'f') from t4; +analyze table t3,t4; + +--echo # This should use a plan with LATERAL DERIVED: +explain select t3.a,t3.c,t.max,t.min +from t3 join +(select a, c, max(b) max, min(b) min from t4 group by a,c) t +on t3.a=t.a and t3.c=t.c +where t3.b > 15; + +--echo # ... and if one adds WITH ROLLUP, then LATERAL DERIVED is no longer used: +explain select t3.a,t3.c,t.max,t.min +from t3 join +(select a, c, max(b) max, min(b) min from t4 group by a,c with rollup) t +on t3.a=t.a and t3.c=t.c +where t3.b > 15; + +drop table t3, t4; + --echo # End of 10.3 tests diff --git a/sql/opt_split.cc b/sql/opt_split.cc index edf9ae3deff..8a985095f3c 100644 --- a/sql/opt_split.cc +++ b/sql/opt_split.cc @@ -310,6 +310,8 @@ struct SplM_field_ext_info: public SplM_field_info occurred also in the select list of this join 9. There are defined some keys usable for ref access of fields from C with available statistics. + 10. The select doesn't use WITH ROLLUP (This limitation can probably be + lifted) @retval true if the answer is positive @@ -326,7 +328,8 @@ bool JOIN::check_for_splittable_materialized() (unit->first_select()->next_select()) || // !(3) (derived->prohibit_cond_pushdown) || // !(4) (derived->is_recursive_with_table()) || // !(5) - (table_count == 0 || const_tables == top_join_tab_count)) // !(6) + (table_count == 0 || const_tables == top_join_tab_count) || // !(6) + rollup.state != ROLLUP::STATE_NONE) // (10) return false; if (group_list) // (7.1) {