MDEV-30608: rpl.rpl_delayed_parallel_slave_sbm sometimes fails with Seconds_Behind_Master should not have used second transaction timestamp
One of the constraints added in the MDEV-29639 patch, is that only
the first event after idling should update last_master_timestamp;
and as long as the replica has more events to execute, the variable
should not be updated. The corresponding test,
rpl_delayed_parallel_slave_sbm.test, aims to verify this; however,
if the IO thread takes too long to queue events, the SQL thread can
appear to catch up too fast.
This fix ensures that the relay log has been fully written before
executing the events.
Note that the underlying cause of this test failure needs to be
addressed as a bug-fix, this is a temporary fix to stop test
failures. To track work on the bug-fix for the underlying issue,
please see MDEV-30619.
This patch fixes the problem by adding a new rule booleat_test.
This makes the grammar clearer and less conflicting.
Additionally, fixing %prec in this grammar branch:
- | boolean_test IS NULL_SYM %prec PREC_BELOW_NOT
+ | boolean_test IS NULL_SYM %prec IS
to have consistently "%prec IS" in all grammar branches starting
with "boolean_test IS ...".
It's not clear why these three rules needed different %prec before the fix:
- boolean_test IS TRUE
- boolean_test IS UNKNOWN
- boolean_test IS NULL
MDEV-28616 Crash when using derived table over union with order by clause
This bug manifested itself when the server processed a query containing
a derived table over union whose ORDER BY clause included a subquery
with unresolvable column reference. For such a query the server crashed
when trying to resolve column references in the ORDER BY clause used by
union.
For any union with ORDER BY clause an extra SELECT_LEX structure is created
and it is attached to SELECT_LEX_UNIT structure of the union via the field
fake_select_lex. The outer context for fake_select_lex must be the same as
for other selects of the union. If the union is used in the FROM list of
a derived table then the outer context for fake_select_lex must be set to
NULL in line with other selects of the union. It was not done and it
caused a crash when searching for possible resolution of an unresolvable
column reference occurred in a subquery used in the ORDER BY clause.
Approved by Oleksandr Byelkin <email address hidden>
