From e99aa91e90adfd54cc1f460dd8cdd19614f30abc Mon Sep 17 00:00:00 2001 From: unknown Date: Wed, 19 Dec 2012 15:56:57 +0200 Subject: MDEV-3928: Assertion `example' failed in Item_cache::is_expensive_processor with a 2-level IN subquery Analysis: The following call stack shows that it is possible to set Item_cache::value_cached, and the relevant value without setting Item_cache::example. #0 Item_cache_temporal::store_packed at item.cc:8395 #1 get_datetime_value at item_cmpfunc.cc:915 #2 resolve_const_item at item.cc:7987 #3 propagate_cond_constants at sql_select.cc:12264 #4 propagate_cond_constants at sql_select.cc:12227 #5 optimize_cond at sql_select.cc:13026 #6 JOIN::optimize at sql_select.cc:1016 #7 st_select_lex::optimize_unflattened_subqueries at sql_lex.cc:3161 #8 JOIN::optimize_unflattened_subqueries at opt_subselect.cc:4880 #9 JOIN::optimize at sql_select.cc:1554 The fix is to set Item_cache_temporal::example even when the value is set directly by Item_cache_temporal::store_packed. This makes the Item_cache_temporal object consistent. --- mysql-test/t/subselect4.test | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'mysql-test/t/subselect4.test') diff --git a/mysql-test/t/subselect4.test b/mysql-test/t/subselect4.test index c9fe4f3d3d5..5e1f3db2f4a 100644 --- a/mysql-test/t/subselect4.test +++ b/mysql-test/t/subselect4.test @@ -1858,5 +1858,33 @@ drop table t1, t2; set optimizer_switch=@subselect4_tmp; +--echo # +--echo # MDEV-3928 Assertion `example' failed in Item_cache::is_expensive_processor with a 2-level IN subquery +--echo # + +CREATE TABLE t1 (a1 INT, b1 TIME) ENGINE=MyISAM; +INSERT INTO t1 VALUES (4,'21:22:34'),(6,'10:50:38'); + +CREATE TABLE t2 (a2 INT, b2 TIME) ENGINE=MyISAM; +INSERT INTO t2 VALUES (8, '06:17:39'); + +CREATE TABLE t3 (a3 INT, b3 TIME) ENGINE=MyISAM; +INSERT INTO t3 VALUES (1,'00:00:01'),(7,'00:00:02'); + +EXPLAIN +SELECT * FROM t1 WHERE a1 IN ( + SELECT a2 FROM t2 WHERE a2 IN ( + SELECT a3 FROM t3 WHERE b2 = b1 AND b2 <= b1 ORDER BY b3 + ) +); + +SELECT * FROM t1 WHERE a1 IN ( + SELECT a2 FROM t2 WHERE a2 IN ( + SELECT a3 FROM t3 WHERE b2 = b1 AND b2 <= b1 ORDER BY b3 + ) +); + +drop table t1, t2, t3; + SET optimizer_switch= @@global.optimizer_switch; set @@tmp_table_size= @@global.tmp_table_size; -- cgit v1.2.1