Allow ColumnarScans to push down join quals by generating
parameterized paths. This significantly expands the utility of chunk
group filtering, making a ColumnarScan behave similar to an index when
on the inner of a nested loop join.
Also, evaluate all parameters on beginscan/rescan, which also works
for external parameters.
Fixes#4488.
Before starting to scan a columnar table, we always flush the pending
writes to disk.
However, we increment command counter after modifying metadata tables.
On the other hand, now that we _don't always use_ xact snapshot to scan
a columnar table, writes that we just flushed might not be visible to
the query that just flushed pending writes to disk since curcid of
provided snapshot would become smaller than the command id being used
when modifying metadata tables.
To give an example, before this change, below was a possible scenario
due to the changes that we made to use the correct snapshot.
```sql
CREATE TABLE t(a int, b int) USING columnar;
BEGIN;
INSERT INTO t VALUES (5, 10);
SELECT * FROM t;
┌───┬───┐
│ a │ b │
├───┼───┤
└───┴───┘
(0 rows)
SELECT * FROM t;
┌───┬────┐
│ a │ b │
├───┼────┤
│ 5 │ 10 │
└───┴────┘
(1 row)
```
The logging of the amount of ignored moves crashed when no distributed
tables existed in a cluster. This also fixes in passing that the logging
of ignored moves logs the correct number of ignored moves if there
exist multiple colocation groups and all are rebalanced at the same time.
In our testing infra structure, even though we use pinned versions of postgres, the auxiliary libraries might pull in newer versions. This is for example the case for libpq, which will now use the libpq libraries from 14beta3.
The changes in this PR are a lot due to the libpq changes.
We also have changed the citus version that is used as a base for the citus upgrades, from 10.0 to 10.1 . This caused columnar to enforce some extra limits on the settings, which conflicted with our upgrade tests.
The changes in failure tests are due to the libpq changes.
There are also a lot of changes on isolation tests outputs, hence we
updated all of them.
Co-authored-by: Nils Dijk <nils@citusdata.com>
* We were anyway not testing reserved_offset in any of those tests
but other fields.
* This only happens with compressed columnar tables and is because the
libzstd/liblz4 versions that we have on exttester ci image might be different
than what we might have on our local environments.
- Add support for CRETE INDEX ... ON ONLY: Before that commit we were not sending "ONLY" option to the worker nodes at all. With this commit, "ONLY" parameter will be sent to the worker nodes if it is necessary. (#4938)
- Add support for ALTER INDEX ... ATTACH PARTITION: Attach child_index to parent_index by creating same inheritance on shard level in addition to table level. (#4980)
* Synchronize hasmetadata flag on mx workers
* Switch to sequential execution
* Add test
* Use SetWorkerColumn
* Add test for stop_sync
* Remove usage of UpdateHasmetadataOnWorkersWithMetadata
* Remove MarkNodeMetadataSynced
* Fix test for metadatasynced
* Remove MarkNodeMetadataSynced
* Style
* Remove MarkNodeHasMetadata
* Remove UpdateDistNodeBoolAttr
* Refactor SetWorkerColumn
* Use SetWorkerColumnLocalOnly when setting up dependencies
* Use SetWorkerColumnLocalOnly in TriggerSyncMetadataToPrimaryNodes
* Style
* Make update command generator functions static
* Set metadatasynced before syncing
* Call SetWorkerColumn only if the sync is successful
* Try to sync all nodes
* Fix indexno
* Update metadatasynced locally first
* Break if a node fails to sync metadata
* Send worker commands optional
* Style & Rebase
* Add raiseOnError param to SetWorkerColumn
* Style
* Set metadatasynced for all metadata nodes
* Style
* Introduce SetWorkerColumnOptional
* Polish
* Style
* Dont send set command to not synced metadata nodes
* Style
* Polish
* Add test for stop_sync
* Add test for shouldhaveshards
* Add test for isactive flag
* Sort by placementid in the function verify_metadata
* Cover edge cases for failing nodes
* Add comments
* Add nodeport to isactive test
* Add warning if metadata out of sync
* Update warning message
As we use the current user to sync the metadata to the nodes
with #5105 (and many other PRs), there is no reason that
prevents us to use the coordinated transaction for metadata syncing.
This commit also renames few functions to reflect their actual
implementation.
Before this commit, creating a partition after a DROP column
on the parent (position before dist. key) was leading to
partition to have the wrong distribution column.
update_distributed_table_colocation can be called by the relation
owner, and internally it updates pg_dist_partition. With this
commit, update_distributed_table_colocation uses an internal
UDF to access pg_dist_partition.
As a result, this operation can now be done by regular users
on MX.
Previously, we were only using chunk group reader for sequential scan.
However, to support index scans on columnar tables, now we use very
same low level functions for index scan too.
Since those low-level functions were only used for sequential scan, it
was guaranteed that we would never read the same chunk group more than
once, so we were freeing chunk buffers after deserializing them into a
separate buffer.
Now that we use those low level functions for index scan, we cannot
free chunk buffers since it's possible to read the same chunk group
again, such that:
- read chunk group 1 of stripe 5
- read chunk group 2 of stripe 5
- read chunk group 1 of stripe 5 again
Here, when we decide to read chunk group 1 for a second time,
chunk group 1 is not cached. Plus, before this commit, we were
freeing the chunk buffers for chunk group 1 after the first
read and then we were getting segfault or errors from low-level
de-compression APIs.
* Fix UNION not being pushdown
Postgres optimizes column fields that are not needed in the output. We
were relying on these fields to understand if it is safe to push down a
union query.
This fix looks at the parse query, which has the original column fields
to detect if it is safe to push down a union query.
* Add more tests
* Simplify code and make it more robust
* Process varlevelsup > 0 in FindReferencedTableColumn
* Only look for outers vars in union path
* Add more comments
* Remove UNION ALL specific logic for pulling up childvars
The progress monitor wouldn't actually update the size of the shard on
the target node when using "block_writes" as the `shard_transfer_mode`.
The reason for this is that the CREATE TABLE part of the shard creation
would only be committed once all data was moved as well. This caused
our size calculation to always return 0, since the table did not exist
yet in the session that the progress monitor used.
This is fixed by first committing creation of the table, and only then
starting the actual data copy.
The test output changes slightly. Apparently splitting this up in two
transactions instead of one, increases the table size after the copy by
about 40kB. The additional size used doesn't increase when with the
amount of data in the table is larger (it stays ~40kB per shard). So
this small change in test output is not considered an actual problem.
These two options were not included when creating the sequences on the
workers as part of metadata syncing.
The missing `data_type` part of the definition made finding the cause
of #5126 harder than necessary, because of confusing errors.
Before this commit, we always synced the metadata with superuser.
However, that creates various edge cases such as visibility errors
or self distributed deadlocks or complicates user access checks.
Instead, with this commit, we use the current user to sync the metadata.
Note that, `start_metadata_sync_to_node` still requires super user
because accessing certain metadata (like pg_dist_node) always require
superuser (e.g., the current user should be a superuser).
However, metadata syncing operations regarding the distributed
tables can now be done with regular users, as long as the user
is the owner of the table. A table owner can still insert non-sense
metadata, however it'd only affect its own table. So, we cannot do
anything about that.
With this commit, we add (`CREATE INDEX` / `REINDEX`) `CONCURRENTLY` support for columnar tables.
For that, we implement `columnar_index_validate_scan` callback.
The reasoning behind the implementation is as follows:
* Postgres function `validate_index` provides all the TIDs that are currently in the
index to `columnar_index_validate_scan` callback via a `tupleSort` object..
* We start scanning the table by using `columnar_getnextslot` as usual.
Before moving forward, note that `columnar_getnextslot` guarantees
to return tuples in the order of their TIDs.
* For us to use during table scan, postgres provides a snapshot guaranteeing
that any tuples that are valid according to that snapshot but are not in the
index must be added to the index.
* Then for each tuple that we read from our table, we continue iterating
given `tupleSort` to find the first TID that is greater than or equal to our
tuple's TID.
If both TID's are equal to each other, then we skip the tuple since it's already
indexed.
If the TID that we read from tupleSort is greater then our tuple's TID, then
we decide to insert this tuple into index.
This happens only when we have a "<" or "<=" filter on distribution
column of a range distributed table and that filter falls in between
two shards.
When the filter falls in between two shards:
If the filter is ">" or ">=", then UpperShardBoundary was
returning "upperBoundIndex - 1", where upperBoundIndex is
exclusive shard index used during binary seach.
This is expected since upperBoundIndex is an exclusive
index.
If the filter is "<" or "<=", then LowerShardBoundary was
returning "lowerBoundIndex + 1", where lowerBoundIndex is
inclusive shard index used during binary seach.
On the other hand, since lowerBoundIndex is an inclusive
index, we should just return lowerBoundIndex instead of
doing "+ 1". Before this commit, we were missing leftmost
shard in such queries.
* Remove useless conditional branches
The branch that we delete from UpperShardBoundary was obviously useless.
The other one in LowerShardBoundary became useless after we remove "+ 1"
from there.
This indeed is another proof of what & how we are fixing with this pr.
* Improve comments and add more
* Add some tests for upper bound calculation too
* Add parameter to cleanup metadata
* Set clear metadata default to true
* Add test for clearing metadata
* Separate test file for start/stop metadata syncing
* Fix stop_sync bug for secondary nodes
* Use PreventInTransactionBlock
* DRemovedebuggiing logs
* Remove relation not found logs from mx test
* Revert localGroupId when doing stop_sync
* Move metadata sync test to mx schedule
* Add test with name that needs to be quoted
* Add test for views and matviews
* Add test for distributed table with custom type
* Add comments to test
* Add test with stats, indexes and constraints
* Fix matview test
* Add test for dropped column
* Add notice messages to stop_metadata_sync
* Add coordinator check to stop metadat sync
* Revert local_group_id only if clearMetadata is true
* Add a final check to see the metadata is sane
* Remove the drop verbosity in test
* Remove table description tests from sync test
* Add stop sync to coordinator test
* Change the order in stop_sync
* Add test for hybrid (columnar+heap) partitioned table
* Change error to notice for stop sync to coordinator
* Sync at the end of the test to prevent any failures
* Add test case in a transaction block
* Remove relation not found tests
Ignore orphaned shards in more places
Only use active shard placements in RouterInsertTaskList
Use IncludingOrphanedPlacements in some more places
Fix comment
Add tests
* Alter seq type when we first use the seq in a dist table
* Don't allow type changes when seq is used in dist table
* ALTER SEQUENCE propagation
* Tests for ALTER SEQUENCE propagation
* Relocate AlterSequenceType and ensure dependencies for sequence
* Support for citus local tables, and other fixes
* Final formatting
Moving shards of reference tables was possible in at least one case:
```sql
select citus_disable_node('localhost', 9702);
create table r(x int);
select create_reference_table('r');
set citus.replicate_reference_tables_on_activate = off;
select citus_activate_node('localhost', 9702);
select citus_move_shard_placement(102008, 'localhost', 9701, 'localhost', 9702);
```
This would then remove the reference table shard on the source, causing
all kinds of issues. This fixes that by disallowing all shard moves
except for shards of distributed tables.
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
With a recent commit, we made (644b266dee)
the behaviour of prepared statements for local cached plans has
slightly changed.
Now, Citus caches the plans when they are re-used. This make triggering
of local cached plans on the 7th execution, and 8th execution is the
first time the plan is used from the cached.
So, the tests are improved to cover 8th execution.
With local query caching, we try to avoid deparse/parse stages as the
operation is too costly.
However, we can do deparse/parse operations once per cached queries, right
before we put the plan into the cache. With that, we avoid edge
cases like (4239) or (5038).
In a sense, we are making the local plan caching behave similar for non-cached
local/remote queries, by forcing to deparse the query once.