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Diffstat (limited to 'mysql-test/t/bug41756.test')
| -rw-r--r-- | mysql-test/t/bug41756.test | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/mysql-test/t/bug41756.test b/mysql-test/t/bug41756.test new file mode 100644 index 00000000000..0d635a6a9f6 --- /dev/null +++ b/mysql-test/t/bug41756.test @@ -0,0 +1,153 @@ +--source include/have_innodb.inc +--echo # +--echo # Bug#41756 Strange error messages about locks from InnoDB +--echo # +--disable_warnings +drop table if exists t1; +--enable_warnings +--echo # In the default transaction isolation mode, and/or with +--echo # innodb_locks_unsafe_for_binlog=OFF, handler::unlock_row() +--echo # in InnoDB does nothing. +--echo # Thus in order to reproduce the condition that led to the +--echo # warning, one needs to relax isolation by either +--echo # setting a weaker tx_isolation value, or by turning on +--echo # the unsafe replication switch. +--echo # For testing purposes, choose to tweak the isolation level, +--echo # since it's settable at runtime, unlike +--echo # innodb_locks_unsafe_for_binlog, which is +--echo # only a command-line switch. +--echo # +set @@session.tx_isolation="read-committed"; + +--echo # Prepare data. We need a table with a unique index, +--echo # for join_read_key to be used. The other column +--echo # allows to control what passes WHERE clause filter. +create table t1 (a int primary key, b int) engine=innodb; +--echo # Let's make sure t1 has sufficient amount of rows +--echo # to exclude JT_ALL access method when reading it, +--echo # i.e. make sure that JT_EQ_REF(a) is always preferred. +insert into t1 values (1,1), (2,null), (3,1), (4,1), + (5,1), (6,1), (7,1), (8,1), (9,1), (10,1), + (11,1), (12,1); +--echo # +--echo # Demonstrate that for the SELECT statement +--echo # used later in the test JT_EQ_REF access method is used. +--echo # +--vertical_results +explain +select 1 from t1 natural join (select 2 as a, 1 as b union all + select 2 as a, 2 as b) as t2 for update; +--horizontal_results +--echo # +--echo # Demonstrate that the reported SELECT statement +--echo # no longer produces warnings. +--echo # +select 1 from t1 natural join (select 2 as a, 1 as b union all + select 2 as a, 2 as b) as t2 for update; +commit; +--echo # +--echo # Demonstrate that due to lack of inter-sweep "reset" function, +--echo # we keep some non-matching records locked, even though we know +--echo # we could unlock them. +--echo # To do that, show that if there is only one distinct value +--echo # for a in t2 (a=2), we will keep record (2,null) in t1 locked. +--echo # But if we add another value for "a" to t2, say 6, +--echo # join_read_key cache will be pruned at least once, +--echo # and thus record (2, null) in t1 will get unlocked. +--echo # +begin; +select 1 from t1 natural join (select 2 as a, 1 as b union all + select 2 as a, 2 as b) as t2 for update; +connect (con1,localhost,root,,); +--echo # +--echo # Switching to connection con1 +connection con1; +--echo # We should be able to delete all records from t1 except (2, null), +--echo # since they were not locked. +begin; +delete from t1 where a in (1,3,4); +delete from t1 where a in (5,6,7); +delete from t1 where a in (8,9,10); +delete from t1 where a in (11,12); +--echo # +--echo # Record (2, null) is locked. This is actually unnecessary, +--echo # because the previous select returned no rows. +--echo # Just demonstrate the effect. +--echo # +--error ER_LOCK_WAIT_TIMEOUT +delete from t1; +rollback; +--echo # +--echo # Switching to connection default +connection default; +--echo # +--echo # Show that the original contents of t1 is intact: +select * from t1; +commit; +--echo # +--echo # Have a one more record in t2 to show that +--echo # if join_read_key cache is purned, the current +--echo # row under the cursor is unlocked (provided, this row didn't +--echo # match the partial WHERE clause, of course). +--echo # Sic: the result of this test dependent on the order of retrieval +--echo # of records --echo # from the derived table, if ! +--echo # We use DELETE to disable the JOIN CACHE. This DELETE modifies no +--echo # records. It also should leave no InnoDB row locks. +--echo # +begin; +delete t1.* from t1 natural join (select 2 as a, 2 as b union all + select 0 as a, 0 as b) as t2; +--echo # Demonstrate that nothing was deleted form t1 +select * from t1; +--echo # +--echo # Switching to connection con1 +connection con1; +begin; +--echo # Since there is another distinct record in the derived table +--echo # the previous matching record in t1 -- (2,null) -- was unlocked. +delete from t1; +--echo # We will need the contents of the table again. +rollback; +select * from t1; +commit; +--echo # +--echo # Switching to connection default +connection default; +commit; +begin; +--echo # +--echo # Before this patch, we could wrongly unlock a record +--echo # that was cached and later used in a join. Demonstrate that +--echo # this is no longer the case. +--echo # Sic: this test is also order-dependent (i.e. the +--echo # the bug would show up only if the first record in the union +--echo # is retreived and processed first. +--echo # +--echo # Verify that JT_EQ_REF is used. +--vertical_results +explain +select 1 from t1 natural join (select 3 as a, 3 as b union all + select 3 as a, 1 as b) as t2 for update; +--horizontal_results +--echo # Lock the record. +select 1 from t1 natural join (select 3 as a, 3 as b union all + select 3 as a, 2 as b) as t2 for update; +--echo # Switching to connection con1 +connection con1; +--echo # +--echo # We should not be able to delete record (3,1) from t1, +--echo # (previously it was possible). +--echo # +--error ER_LOCK_WAIT_TIMEOUT +delete from t1 where a=3; +--echo # Switching to connection default +connection default; +commit; + +disconnect con1; +set @@session.tx_isolation=default; +drop table t1; + +--echo # +--echo # End of 5.0 tests +--echo # |