revision-id: 7c56f46d611eda7dadde83fa4049c2121d42382d (mariadb-10.3.18-190-g7c56f46) parent(s): 44298e4dea39280187c587c6e776ce8d04e350de author: Igor Babaev committer: Igor Babaev timestamp: 2020-03-23 19:20:48 -0700 message: MDEV-21883 Server crashes when joining a subselect with 32 tables and GROUP BY This bug could cause a crash for any query that used a derived table/view/CTE whose specification was a SELECT with a GROUP BY clause and a FROM list containing 32 or more table references. The problem appeared only in the cases when the splitting optimization could be applied to such derived table/view/CTE. --- mysql-test/main/derived_cond_pushdown.result | 85 ++++++++++++++++++++++++++++ mysql-test/main/derived_cond_pushdown.test | 51 +++++++++++++++++ sql/opt_split.cc | 2 +- 3 files changed, 137 insertions(+), 1 deletion(-) diff --git a/mysql-test/main/derived_cond_pushdown.result b/mysql-test/main/derived_cond_pushdown.result index 1ae78ae..532a6cc 100644 --- a/mysql-test/main/derived_cond_pushdown.result +++ b/mysql-test/main/derived_cond_pushdown.result @@ -16918,4 +16918,89 @@ Warnings: Note 1003 /* select#1 */ select `test`.`t1`.`id` AS `id`,`test`.`t1`.`a` AS `a` from `test`.`t1` semi join ((/* select#3 */ select `test`.`t1`.`id` AS `id`,`test`.`t1`.`a` AS `a` from `test`.`t1` left join `test`.`t2` on(`test`.`t2`.`ro_id` = `test`.`t1`.`id` and `test`.`t2`.`flag` = 1) where `test`.`t1`.`id` = `test`.`t1`.`id` group by `test`.`t1`.`id`) `dt`) where `dt`.`id` = `test`.`t1`.`id` drop view v1; drop table t1,t2; +# +# MDEV-21883: potentially splittable materialized derived +# that uses a join of 32 tables +# +CREATE TABLE t (id INT NOT NULL PRIMARY KEY); +INSERT INTO t values (1),(2),(3); +set statement optimizer_switch='split_materialized=off' for SELECT t.id FROM t +LEFT JOIN ( +SELECT t0.id FROM t AS t0 +LEFT JOIN t AS t1 ON 0=1 +LEFT JOIN t AS t2 ON 0=1 +LEFT JOIN t AS t3 ON 0=1 +LEFT JOIN t AS t4 ON 0=1 +LEFT JOIN t AS t5 ON 0=1 +LEFT JOIN t AS t6 ON 0=1 +LEFT JOIN t AS t7 ON 0=1 +LEFT JOIN t AS t8 ON 0=1 +LEFT JOIN t AS t9 ON 0=1 +LEFT JOIN t AS t10 ON 0=1 +LEFT JOIN t AS t11 ON 0=1 +LEFT JOIN t AS t12 ON 0=1 +LEFT JOIN t AS t13 ON 0=1 +LEFT JOIN t AS t14 ON 0=1 +LEFT JOIN t AS t15 ON 0=1 +LEFT JOIN t AS t16 ON 0=1 +LEFT JOIN t AS t17 ON 0=1 +LEFT JOIN t AS t18 ON 0=1 +LEFT JOIN t AS t19 ON 0=1 +LEFT JOIN t AS t20 ON 0=1 +LEFT JOIN t AS t21 ON 0=1 +LEFT JOIN t AS t22 ON 0=1 +LEFT JOIN t AS t23 ON 0=1 +LEFT JOIN t AS t24 ON 0=1 +LEFT JOIN t AS t25 ON 0=1 +LEFT JOIN t AS t26 ON 0=1 +LEFT JOIN t AS t27 ON 0=1 +LEFT JOIN t AS t28 ON 0=1 +LEFT JOIN t AS t29 ON 0=1 +LEFT JOIN t AS t30 ON 0=1 +LEFT JOIN t AS t31 ON 0=1 +GROUP BY t0.id) AS dt ON dt.id = t.id; +id +1 +2 +3 +set statement optimizer_switch='split_materialized=on' for SELECT t.id FROM t +LEFT JOIN ( +SELECT t0.id FROM t AS t0 +LEFT JOIN t AS t1 ON 0=1 +LEFT JOIN t AS t2 ON 0=1 +LEFT JOIN t AS t3 ON 0=1 +LEFT JOIN t AS t4 ON 0=1 +LEFT JOIN t AS t5 ON 0=1 +LEFT JOIN t AS t6 ON 0=1 +LEFT JOIN t AS t7 ON 0=1 +LEFT JOIN t AS t8 ON 0=1 +LEFT JOIN t AS t9 ON 0=1 +LEFT JOIN t AS t10 ON 0=1 +LEFT JOIN t AS t11 ON 0=1 +LEFT JOIN t AS t12 ON 0=1 +LEFT JOIN t AS t13 ON 0=1 +LEFT JOIN t AS t14 ON 0=1 +LEFT JOIN t AS t15 ON 0=1 +LEFT JOIN t AS t16 ON 0=1 +LEFT JOIN t AS t17 ON 0=1 +LEFT JOIN t AS t18 ON 0=1 +LEFT JOIN t AS t19 ON 0=1 +LEFT JOIN t AS t20 ON 0=1 +LEFT JOIN t AS t21 ON 0=1 +LEFT JOIN t AS t22 ON 0=1 +LEFT JOIN t AS t23 ON 0=1 +LEFT JOIN t AS t24 ON 0=1 +LEFT JOIN t AS t25 ON 0=1 +LEFT JOIN t AS t26 ON 0=1 +LEFT JOIN t AS t27 ON 0=1 +LEFT JOIN t AS t28 ON 0=1 +LEFT JOIN t AS t29 ON 0=1 +LEFT JOIN t AS t30 ON 0=1 +LEFT JOIN t AS t31 ON 0=1 +GROUP BY t0.id) AS dt ON dt.id = t.id; +id +1 +2 +3 +DROP TABLE t; # End of 10.3 tests diff --git a/mysql-test/main/derived_cond_pushdown.test b/mysql-test/main/derived_cond_pushdown.test index 525122e..592f23d 100644 --- a/mysql-test/main/derived_cond_pushdown.test +++ b/mysql-test/main/derived_cond_pushdown.test @@ -3371,4 +3371,55 @@ eval explain extended $q2; drop view v1; drop table t1,t2; +--echo # +--echo # MDEV-21883: potentially splittable materialized derived +--echo # that uses a join of 32 tables +--echo # + +CREATE TABLE t (id INT NOT NULL PRIMARY KEY); +INSERT INTO t values (1),(2),(3); + +let $q= +SELECT t.id FROM t +LEFT JOIN ( + SELECT t0.id FROM t AS t0 + LEFT JOIN t AS t1 ON 0=1 + LEFT JOIN t AS t2 ON 0=1 + LEFT JOIN t AS t3 ON 0=1 + LEFT JOIN t AS t4 ON 0=1 + LEFT JOIN t AS t5 ON 0=1 + LEFT JOIN t AS t6 ON 0=1 + LEFT JOIN t AS t7 ON 0=1 + LEFT JOIN t AS t8 ON 0=1 + LEFT JOIN t AS t9 ON 0=1 + LEFT JOIN t AS t10 ON 0=1 + LEFT JOIN t AS t11 ON 0=1 + LEFT JOIN t AS t12 ON 0=1 + LEFT JOIN t AS t13 ON 0=1 + LEFT JOIN t AS t14 ON 0=1 + LEFT JOIN t AS t15 ON 0=1 + LEFT JOIN t AS t16 ON 0=1 + LEFT JOIN t AS t17 ON 0=1 + LEFT JOIN t AS t18 ON 0=1 + LEFT JOIN t AS t19 ON 0=1 + LEFT JOIN t AS t20 ON 0=1 + LEFT JOIN t AS t21 ON 0=1 + LEFT JOIN t AS t22 ON 0=1 + LEFT JOIN t AS t23 ON 0=1 + LEFT JOIN t AS t24 ON 0=1 + LEFT JOIN t AS t25 ON 0=1 + LEFT JOIN t AS t26 ON 0=1 + LEFT JOIN t AS t27 ON 0=1 + LEFT JOIN t AS t28 ON 0=1 + LEFT JOIN t AS t29 ON 0=1 + LEFT JOIN t AS t30 ON 0=1 + LEFT JOIN t AS t31 ON 0=1 + GROUP BY t0.id) AS dt ON dt.id = t.id; + +eval set statement optimizer_switch='split_materialized=off' for $q; + +eval set statement optimizer_switch='split_materialized=on' for $q; + +DROP TABLE t; + --echo # End of 10.3 tests diff --git a/sql/opt_split.cc b/sql/opt_split.cc index 6f8248c..c70fac4 100644 --- a/sql/opt_split.cc +++ b/sql/opt_split.cc @@ -968,7 +968,7 @@ SplM_plan_info * JOIN_TAB::choose_best_splitting(double record_count, The plan for the chosen key has not been found in the cache. Build a new plan and save info on it in the cache */ - table_map all_table_map= (1 << join->table_count) - 1; + table_map all_table_map= (((table_map) 1) << join->table_count) - 1; reset_validity_vars_for_keyuses(best_key_keyuse_ext_start, best_table, best_key, remaining_tables, true); choose_plan(join, all_table_map & ~join->const_table_map);