mariadb/mysql-test/r/bug41756.result

#
# Bug#41756 Strange error messages about locks from InnoDB
#
drop table if exists t1;
# In the default transaction isolation mode, and/or with
# innodb_locks_unsafe_for_binlog=OFF, handler::unlock_row()
# in InnoDB does nothing.
# Thus in order to reproduce the condition that led to the
# warning, one needs to relax isolation by either
# setting a weaker tx_isolation value, or by turning on
# the unsafe replication switch.
# For testing purposes, choose to tweak the isolation level,
# since it's settable at runtime, unlike
# innodb_locks_unsafe_for_binlog, which is
# only a command-line switch.
#
set @@session.tx_isolation="read-committed";
# Prepare data. We need a table with a unique index,
# for join_read_key to be used. The other column
# allows to control what passes WHERE clause filter.
create table t1 (a int primary key, b int) engine=innodb;
# Let's make sure t1 has sufficient amount of rows
# to exclude JT_ALL access method when reading it,
# 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);
#
# Demonstrate that for the SELECT statement
# used later in the test JT_EQ_REF access method is used.
#
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;
id	1
select_type	PRIMARY
table	<derived2>
type	ALL
possible_keys	NULL
key	NULL
key_len	NULL
ref	NULL
rows	2
Extra	
id	1
select_type	PRIMARY
table	t1
type	eq_ref
possible_keys	PRIMARY
key	PRIMARY
key_len	4
ref	t2.a
rows	1
Extra	Using where
id	2
select_type	DERIVED
table	NULL
type	NULL
possible_keys	NULL
key	NULL
key_len	NULL
ref	NULL
rows	NULL
Extra	No tables used
id	3
select_type	UNION
table	NULL
type	NULL
possible_keys	NULL
key	NULL
key_len	NULL
ref	NULL
rows	NULL
Extra	No tables used
id	NULL
select_type	UNION RESULT
table	<union2,3>
type	ALL
possible_keys	NULL
key	NULL
key_len	NULL
ref	NULL
rows	NULL
Extra	
#
# Demonstrate that the reported SELECT statement
# no longer produces warnings.
#
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;
1
commit;
# 
# Demonstrate that due to lack of inter-sweep "reset" function,
# we keep some non-matching records locked, even though we know
# we could unlock them.
# To do that, show that if there is only one distinct value
# for a in t2 (a=2), we will keep record (2,null) in t1 locked.
# But if we add another value for "a" to t2, say 6,
# join_read_key cache will be pruned at least once, 
# and thus record (2, null) in t1 will get unlocked.
#
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;
1
#
# Switching to connection con1
# We should be able to delete all records from t1 except (2, null),
# 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);
# 
# Record (2, null) is locked. This is actually unnecessary, 
# because the previous select returned no rows. 
# Just demonstrate the effect.
#
delete from t1;
ERROR HY000: Lock wait timeout exceeded; try restarting transaction
rollback;
#
# Switching to connection default
#
# Show that the original contents of t1 is intact:
select * from t1;
a	b
1	1
2	NULL
3	1
4	1
5	1
6	1
7	1
8	1
9	1
10	1
11	1
12	1
commit;
#
# Have a one more record in t2 to show that 
# if join_read_key cache is purned, the current
# row under the cursor is unlocked (provided, this row didn't 
# match the partial WHERE clause, of course).
# Sic: the result of this test dependent on the order of retrieval
# of records --echo # from the derived table, if !
# We use DELETE to disable the JOIN CACHE. This DELETE modifies no
# records. It also should leave no InnoDB row locks.
#
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;
# Demonstrate that nothing was deleted form t1
select * from t1;
a	b
1	1
2	NULL
3	1
4	1
5	1
6	1
7	1
8	1
9	1
10	1
11	1
12	1
#
# Switching to connection con1
begin;
# Since there is another distinct record in the derived table
# the previous matching record in t1 -- (2,null) -- was unlocked.
delete from t1;
# We will need the contents of the table again.
rollback;
select * from t1;
a	b
1	1
2	NULL
3	1
4	1
5	1
6	1
7	1
8	1
9	1
10	1
11	1
12	1
commit;
#
# Switching to connection default
commit;
begin;
#
# Before this patch, we could wrongly unlock a record
# that was cached and later used in a join. Demonstrate that
# this is no longer the case.
# Sic: this test is also order-dependent (i.e. the
# the bug would show up only if the first record in the union
# is retreived and processed first.
#
# Verify that JT_EQ_REF is used.
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;
id	1
select_type	PRIMARY
table	t1
type	ALL
possible_keys	PRIMARY
key	NULL
key_len	NULL
ref	NULL
rows	1
Extra	
id	1
select_type	PRIMARY
table	<derived2>
type	ALL
possible_keys	NULL
key	NULL
key_len	NULL
ref	NULL
rows	2
Extra	Using where
id	2
select_type	DERIVED
table	NULL
type	NULL
possible_keys	NULL
key	NULL
key_len	NULL
ref	NULL
rows	NULL
Extra	No tables used
id	3
select_type	UNION
table	NULL
type	NULL
possible_keys	NULL
key	NULL
key_len	NULL
ref	NULL
rows	NULL
Extra	No tables used
id	NULL
select_type	UNION RESULT
table	<union2,3>
type	ALL
possible_keys	NULL
key	NULL
key_len	NULL
ref	NULL
rows	NULL
Extra	
# 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;
1
# Switching to connection con1
#
# We should not be able to delete record (3,1) from t1,
# (previously it was possible).
#
delete from t1 where a=3;
ERROR HY000: Lock wait timeout exceeded; try restarting transaction
# Switching to connection default
commit;
set @@session.tx_isolation=default;
drop table t1;
#
# End of 5.0 tests
#