diff --git a/mysql-test/r/explain.result b/mysql-test/r/explain.result index b8dbb54e5fb..b9ae362f6cd 100644 --- a/mysql-test/r/explain.result +++ b/mysql-test/r/explain.result @@ -271,4 +271,50 @@ EXPLAIN SELECT c1 FROM t1 WHERE c2 = 1 AND c4 = 1 AND c5 = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref c2,c2_2 c2 10 const,const 3 Using where DROP TABLE t1; +# +# Bug#56814 Explain + subselect + fulltext crashes server +# +CREATE TABLE t1(f1 VARCHAR(6) NOT NULL, +FULLTEXT KEY(f1),UNIQUE(f1)); +INSERT INTO t1 VALUES ('test'); +EXPLAIN SELECT 1 FROM t1 +WHERE 1 > ALL((SELECT 1 FROM t1 JOIN t1 a ON (MATCH(t1.f1) AGAINST ("")) +WHERE t1.f1 GROUP BY t1.f1)); +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY t1 system NULL NULL NULL NULL 1 +2 SUBQUERY a system NULL NULL NULL NULL 1 Using filesort +2 SUBQUERY t1 fulltext f1 f1 0 1 Using where +PREPARE stmt FROM +'EXPLAIN SELECT 1 FROM t1 + WHERE 1 > ALL((SELECT 1 FROM t1 RIGHT OUTER JOIN t1 a + ON (MATCH(t1.f1) AGAINST ("")) + WHERE t1.f1 GROUP BY t1.f1))'; +EXECUTE stmt; +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY t1 system NULL NULL NULL NULL 1 +2 SUBQUERY a system NULL NULL NULL NULL 1 Using filesort +2 SUBQUERY t1 fulltext f1 f1 0 1 Using where +EXECUTE stmt; +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY t1 system NULL NULL NULL NULL 1 +2 SUBQUERY a system NULL NULL NULL NULL 1 Using filesort +2 SUBQUERY t1 fulltext f1 f1 0 1 Using where +DEALLOCATE PREPARE stmt; +PREPARE stmt FROM +'EXPLAIN SELECT 1 FROM t1 + WHERE 1 > ALL((SELECT 1 FROM t1 JOIN t1 a + ON (MATCH(t1.f1) AGAINST ("")) + WHERE t1.f1 GROUP BY t1.f1))'; +EXECUTE stmt; +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY t1 system NULL NULL NULL NULL 1 +2 SUBQUERY a system NULL NULL NULL NULL 1 Using filesort +2 SUBQUERY t1 fulltext f1 f1 0 1 Using where +EXECUTE stmt; +id select_type table type possible_keys key key_len ref rows Extra +1 PRIMARY t1 system NULL NULL NULL NULL 1 +2 SUBQUERY a system NULL NULL NULL NULL 1 Using filesort +2 SUBQUERY t1 fulltext f1 f1 0 1 Using where +DEALLOCATE PREPARE stmt; +DROP TABLE t1; End of 5.1 tests. diff --git a/mysql-test/t/explain.test b/mysql-test/t/explain.test index 60108b3b038..931948b1b65 100644 --- a/mysql-test/t/explain.test +++ b/mysql-test/t/explain.test @@ -238,4 +238,40 @@ EXPLAIN SELECT c1 FROM t1 WHERE c2 = 1 AND c4 = 1 AND c5 = 1; DROP TABLE t1; +--echo # +--echo # Bug#56814 Explain + subselect + fulltext crashes server +--echo # + +CREATE TABLE t1(f1 VARCHAR(6) NOT NULL, +FULLTEXT KEY(f1),UNIQUE(f1)); +INSERT INTO t1 VALUES ('test'); + +EXPLAIN SELECT 1 FROM t1 +WHERE 1 > ALL((SELECT 1 FROM t1 JOIN t1 a ON (MATCH(t1.f1) AGAINST ("")) +WHERE t1.f1 GROUP BY t1.f1)); + +PREPARE stmt FROM +'EXPLAIN SELECT 1 FROM t1 + WHERE 1 > ALL((SELECT 1 FROM t1 RIGHT OUTER JOIN t1 a + ON (MATCH(t1.f1) AGAINST ("")) + WHERE t1.f1 GROUP BY t1.f1))'; + +EXECUTE stmt; +EXECUTE stmt; + +DEALLOCATE PREPARE stmt; + +PREPARE stmt FROM +'EXPLAIN SELECT 1 FROM t1 + WHERE 1 > ALL((SELECT 1 FROM t1 JOIN t1 a + ON (MATCH(t1.f1) AGAINST ("")) + WHERE t1.f1 GROUP BY t1.f1))'; + +EXECUTE stmt; +EXECUTE stmt; + +DEALLOCATE PREPARE stmt; + +DROP TABLE t1; + --echo End of 5.1 tests. diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc index 5cf585e1a56..c1b1f47e5e9 100644 --- a/sql/item_subselect.cc +++ b/sql/item_subselect.cc @@ -1910,21 +1910,26 @@ int subselect_single_select_engine::exec() DBUG_RETURN(join->error ? join->error : 1); } if (!select_lex->uncacheable && thd->lex->describe && - !(join->select_options & SELECT_DESCRIBE) && - join->need_tmp) + !(join->select_options & SELECT_DESCRIBE)) { item->update_used_tables(); if (item->const_item()) { + /* + It's necessary to keep original JOIN table because + create_sort_index() function may overwrite original + JOIN_TAB::type and wrong optimization method can be + selected on re-execution. + */ + select_lex->uncacheable|= UNCACHEABLE_EXPLAIN; + select_lex->master_unit()->uncacheable|= UNCACHEABLE_EXPLAIN; /* Force join->join_tmp creation, because this subquery will be replaced by a simple select from the materialization temp table by optimize() called by EXPLAIN and we need to preserve the initial query structure so we can display it. */ - select_lex->uncacheable|= UNCACHEABLE_EXPLAIN; - select_lex->master_unit()->uncacheable|= UNCACHEABLE_EXPLAIN; - if (join->init_save_join_tab()) + if (join->need_tmp && join->init_save_join_tab()) DBUG_RETURN(1); /* purecov: inspected */ } } diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 363e0a4ad8a..e284f554d8c 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -2514,6 +2514,13 @@ mysql_select(THD *thd, Item ***rref_pointer_array, { DBUG_RETURN(TRUE); } + /* + Original join tabs might be overwritten at first + subselect execution. So we need to restore them. + */ + Item_subselect *subselect= select_lex->master_unit()->item; + if (subselect && subselect->is_uncacheable() && join->reinit()) + DBUG_RETURN(TRUE); } else { @@ -8956,6 +8963,13 @@ simplify_joins(JOIN *join, List *join_list, COND *conds, bool top) that reject nulls => the outer join can be replaced by an inner join. */ table->outer_join= 0; + /* + Update TABLE::maybe_null field as it could have + the value(maybe_null==TRUE) based on the assumption + that this join is outer(see setup_table_map() func). + */ + if (table->table) + table->table->maybe_null= FALSE; if (table->on_expr) { /* Add on expression to the where condition. */