PG16 compatibility - part 9
Check out part 1 42d956888d
part 2 0d503dd5ac
part 3 907d72e60d
part 4 7c6b4ce103
part 5 6056cb2c29
part 6 b36c431abb
part 7 ee3153fe50
part 8 2c50b5f7ff
This commit is in the series of PG16 compatibility commits. It makes some changes
to our tests in order to be compatible with the following in PG16:
- Fix multi_subquery_in_where_reference_clause test
somehow PG got rid of the outer join
(e.g., explain doesn't show outer joins),
hence we can pushdown the subquery.
Changing to users_reference_table
- Fix unqualified column names for views in PG16
Relevant PG commit:
47bb9db759
47bb9db75996232ea71fc1e1888ffb0e70579b54
- Fix global_cancel test
Error wording and detail changed
Relevant PG commit:
2631ebab7b
2631ebab7b18bdc079fd86107c47d6104a6b3c6e
- Fix local_table_join_test with lateral subquery
Possible relevant PG commit:
ae89129aa3
ae89129aa3555c263b8c3ccc4c0f1ef7e46201aa
I removed the where clause and the limit count error was hit again.
With the where clause the query unexpectedly works.
- Fix test outputs
Relevant PG commits:
-- 1349d2790b
-- f4c7c410ee
For multi_explain and multi_complex_count_distinct there were too many places
touched so I just added an alternative test output.
For the other tests I modified the problematic parts.
More PG16 compatibility commits are coming soon ...
DESCRIPTION: Fix bug in global PID assignment for rebalancer
sub-connections
In CI our isolation_shard_rebalancer_progress test would sometimes fail
like this:
```diff
+isolationtester: canceling step s1-rebalance-c1-block-writes after 60 seconds
step s1-rebalance-c1-block-writes:
SELECT rebalance_table_shards('colocated1', shard_transfer_mode:='block_writes');
- <waiting ...>
+
+ERROR: canceling statement due to user request
step s7-get-progress:
```
Source:
https://app.circleci.com/pipelines/github/citusdata/citus/27855/workflows/2a7e335a-f3e8-46ed-b6bd-6920d42f7214/jobs/831710
It turned out this was an actual bug in the way our assigning of global
PIDs interacts with the way we connect to ourselves as the shard
rebalancer. The first command the shard rebalancer sends is a SET
ommand to change the application_name to `citus_rebalancer`. If
`StartupCitusBackend` is called after this command is processed, then it
overwrites the global PID that was extracted from the previous
application_name. This makes sure that we don't do that, and continue to
use the original global PID. While it might seem that we only call
`StartupCitusBackend` once for each query backend, this isn't actually
the case. Whenever pg_dist_partition gets ANALYZEd by autovacuum
we indirectly call `StartupCitusBackend` again, because we invalidate
the cache then.
In passing this fixes two other things as well:
1. It sets `distributedCommandOriginator` correctly in
`AssignGlobalPID`, by using IsExternalClientBackend(). This doesn't
matter much anymore, since AssignGlobalPID effectively becomes a
no-op in this PR for any non-external client backends.
2. It passes the application_name to InitializeBackendData in
StartupCitusBackend, instead of INVALID_CITUS_INTERNAL_BACKEND_GPID
(which effectively got casted to NULL). In practice this doesn't
change the behaviour of the call, since the call is a no-op for every
backend except the maintenance daemon. And the behaviour of the call
is the same for NULL as for the application_name of the maintenance
daemon.
And also citus_calculate_gpid(nodeId,pid). These UDFs are just
wrappers for the existing functions. Useful for testing and simple
manipulation of citus_stat_activity.