Since PG14 we can now use binary encoding for arrays and composite types
that contain user defined types. This was fixed in this commit in
Postgres: 670c0a1d47
This change starts using that knowledge, by not necessarily falling back
to text encoding anymore for those types.
While doing this and testing a bit more I found various cases where
binary encoding would fail that our checks didn't cover. This fixes
those cases and adds tests for those. It also fixes EXPLAIN ANALYZE
never using binary encoding, which was a leftover of workaround that
was not necessary anymore.
Finally, it changes the default for both `citus.enable_binary_protocol`
and `citus.binary_worker_copy_format` to `true` for PG14 and up. In our
cloud offering `binary_worker_copy_format` already was true by default.
`enable_binary_protocol` had some bug with MX and user defined types,
this bug was fixed by the above mentioned fixes.
- get_missing_time_partition_ranges: Gets the ranges of missing partitions for the given table, interval and range unless any existing partition conflicts with calculated missing ranges.
- create_time_partitions: Creates partitions by getting range values from get_missing_time_partition_ranges.
- drop_old_time_partitions: Drops partitions of the table older than given threshold.
* Rename RecostColumnarPaths to CostColumnarPaths
* Rename RecostColumnarIndexPath to CostColumnarIndexPath
* Reorder args of CostColumnarScan to align with other two costing functions
* Not adjust index scan start-up cost
* Rename ColumnarIndexScanAddTotalCost to ColumnarIndexScanAdditionalCost
* Reflect that index scan will at least read one stripe in totalCost calculation
* Organize declarations in columnar_customscan.c
In PG 14, procedures can have OUT parameters. In Citus' procedure
delegation framework, we need to adjust the function expression
to get the outargs parameters.
Releven PG change:
e56bce5d43
Simply call Postgres' function to report the progress on
each row recieved.
Note that we currently do not support "COPY dist/ref TO .." progress
report nicely. Citus has some specialized logic to support
"COPY dist/ref TO .." such that it either converts the underlying
command into "COPY (SELECT * FROM dist/ref ) ..." or sends COPY
command to shards directly. In the former case, "tuples_processed"
is only updated when the executor returns all the tuples, so the
progress is not accurate. In the latter case, Citus can actually
implement the progress report. But, for the sake of consistency,
we prefer to not implement at all.
Added to PG 14 with https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=8a4f618e7ae3cb11b0b37d0f06f05c8ff905833f
Postgres changed stats expression types as of PG14. Hence we needed to
write the AppendColumnNames method. Also they removed the error on PG
side so we remove it as well.
Relevant commits on pg14:
a4d75c86bf15220df22de0a92c819ecef9db3849
388e75ad33489b77cfb9a8590a91e9287d8fb960
When queryId is not 0 and verbose is true, the query identifier is
emitted to the explain output. This is breaking Postgres outputs.
We disable de query identifier calculation in the tests.
Commit on PG that introduced the query identifier in the explain output:
4f0b0966c866ae9f0e15d7cc73ccf7ce4e1af84b
These changes were removed in commit: Introduces ExecSimpleRelationInsert_compat and modifyStateResultRelInfo macros
We shouldn't have removed them but instead kept them for before PG14
Relevant PG commit:
9e38c2bb5093ceb0c04d6315ccd8975bd17add66
fix array_cat_agg for pg upgrades
array_cat_agg now needs to take anycompatiblearray instead of anyarray
because array_cat changed its type from anyarray to anycompatiblearray
with pg14.
To handle upgrades correctly, we drop the aggregate in
citus_pg_prepare_upgrade. To be able to drop it, we first remove the
dependency from pg_depend.
Then we create the right aggregate in citus_finish_pg_upgrade and we
also add the dependency back to pg_depend.
Postgres doesn't accept NULL for queryStrings in explain plans anymore.
Internally, there are some places in Postgres where they modified the
NULLS to ""(the empty string). So we do the same on citus side.
Commit on Postgres:
1111b2668d89bfcb6f502789158b1233ab4217a6
Postgres expects to set the HASH_STRINGS explicitly in case of the
default behaivor for string hash function.
Postgres Commit
b3817f5f774663d55931dd4fab9c5a94a15ae7ab
index_insert function now has a new parameter, indexUnchanged
This new macro give us the ability to use these new parameter for PG14 and they don't give the parameters for previous versions
Existing parameter is set to false
Relevant PG commit:
9dc718bdf2b1a574481a45624d42b674332e2903
es_result_relation_info is removed from Estate. In this commit we make some changes to handle that.
resultRelationInfo filed is added to ModifyState to support the removed field.
Relevant PG commits:
1375422c7826a2bf387be29895e961614f69de4b
a04daa97a4339c38e304cd6164d37da540d665a8
GetOldestXmin function is removed so we use GetOldestNonRemovableTransactionId functions instead
GetOldestNonRemovableTransactionId_compat picks the appropriate one
Relevant PG commit:
dc7420c2c9274a283779ec19718d2d16323640c0
get_partition_parent and RelationGetPartitionDesc functions now have new parameters to also include detached partitions
Thess new macros give us the ability to use these new parameter for PG14 and they don't give the parameters for previous versions
Existing parameters are set to not accept detached partitions
Relevant PG commit:
71f4c8c6f74ba021e55d35b1128d22fb8c6e1629
In two commits vacuumFlags in PGXACT is moved and then renamed to status flags
This macro uses the appropriate version of the flag
Relevant PG commits:
5788e258bb26495fab65ff3aa486268d1c50b123
cd9c1b3e197a9b53b840dcc87eb41b04d601a5f9
SetTuplestoreDestReceiverParams function now has two new parameters
This new macro give us the ability to use this new parameter for PG14 and it doesn't give the parameter for previous versions
Existing parameters are set to NULL to keep previous behavior
Relevant PG commit:
2f48ede080f42b97b594fb14102c82ca1001b80c
Some Copy related functions copied from Postgres had support for both old and new protocols
Postgres removed support for old version so we remove it too
Relevant PG commit:
3174d69fb96a66173224e60ec7053b988d5ed4d9
New macros: standard_ProcessUtility_compat, ProcessUtility_compat, ColumnarProcessUtility_compat, PrevProcessUtilityHook_compat
The functions now have a new bool parameter: readOnlyTree
These new macros give us the ability to use this new parameter for PG14 and it doesn't give the parameter for previous versions
In multi_ProcessUtility and ColumnarProcessUtility, before doing anything else, we check if readOnlyTree parameter is true and create a copy of pstmt
Existing readOnlyTree parameters are set to false since we already handle the read only case at multi_ProcessUtility and ColumnarProcessUtility
Relevant PG commit:
7c337b6b527b7052e6a751f966d5734c56f668b5
This function was copied from Postgres but it is not static at PG14
So we keep the definition only for previous versions
Relevant PG commit:
c532d15dddff14b01fe9ef1d465013cb8ef186df
CopyState struct is divided into parts and one of them is CopyFromState
This macro uses the appropriate one for PG versions
Relevant PG commit:
c532d15dddff14b01fe9ef1d465013cb8ef186df
In ReindexStmt concurrent field is moved to options and then options are converted to params list.
This macro uses previous fields for previous versions and the new params list with a new function named IsReindexWithParam for PG14
Relevant PG commits:
844c05abc3f1c1703bf17cf44ab66351ed9711d2
b5913f6120792465f4394b93c15c2e2ac0c08376
VacOptTernaryValue enum is renamed to VacOptValue.
In the enum there were three values, VACOPT_TERNARY_DEFAULT, VACOPT_TERNARY_DISABLED, and VACOPT_TERNARY_ENABLED
Now there are four values VACOPTVALUE_UNSPECIFIED, VACOPTVALUE_AUTO, VACOPTVALUE_DISABLED, and VACOPTVALUE_ENABLED
New macros are VacOptValue_compat, VACOPTVALUE_UNSPECIFIED_COMPAT, VACOPTVALUE_DISABLED_COMPAT, and VACOPTVALUE_ENABLED_COMPAT
The VACOPTVALUE_UNSPECIFIED_COMPAT matches VACOPT_TERNARY_DEFAULT and VACOPTVALUE_UNSPECIFIED. And there are no macro for VACOPTVALUE_AUTO.
Relevant PG commit:
3499df0dee8c4ea51d264a674df5b5e31991319a
New macros: FuncnameGetCandidates_compat and expand_function_arguments_compat
The functions (the ones without _compat) now have a new bool include_out_arguments parameter
These new macros give us the ability to use this new parameter for PG14 and it doesn't give the parameter for previous versions
Existing include_out_arguments parameters are set to 'false' to keep current behavior
Relevant PG commit:
e56bce5d43789cce95d099554ae9593ada92b3b7
stats function now have a new bool print_to_stderr parameter
This new macro gives us the ability to use this new parameter for PG14 and it doesn't give the parameter for previous versions
Existing print_to_stderr parameter is set to true to keep current behavior
Relevant PG commit:
43620e328617c1f41a2a54c8cee01723064e3ffa
getObjectTypeDescription and getObjectIdentity functions now have a new bool missing_ok parameter
These new macros give us the ability to use this new parameter for PG14 and they don't give the parameter for previous versions
Currently all missing_ok parameters are set to false to keep current behavior
Relevant PG commit:
2a10fdc4307a667883f7a3369cb93a721ade9680
The STATUS_WAITING define is removed and an enum with PROC_WAIT_STATUS_WAITING is added instead
This macro uses appropriate one
Relevant PG commit:
a513f1dfbf2c29a51b0f7cbd5913ce2d2ee452c5
AlterTableStmt's relkind field is changed into objtype
New AlterTableStmtObjType macro uses the appropriate one
Relevant PG commit:
cc35d8933a211d9965eb1c1d2749a903d5735db2
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.
Previously, we were doing `first_row_number` reservation for the first
row written to current `WriteState` but were doing `stripe_id`
reservation when flushing the `WriteState` and were inserting the
related record to `columnar.stripe` at that time as well.
However, inserting `columnar.stripe` record at flush-time is
problematic. This is because, as told in #5160, if relation has
any index-based constraints and if there are two concurrent
writes that are inserting conflicting key values for that constraint,
then postgres relies on `tableAM->fetch_index_tuple`
(=`columnar_fetch_index_tuple`) callback to return `true` when
indexAM is checking against possible constraint violations.
However, pending writes of other backends are not visible to concurrent
sessions in columnar since we were not inserting the stripe metadata
record until flushing the stripe.
With this commit, we split stripe reservation into two phases:
i) Reserve `stripe_id` and insert a "dummy" record to `columnar.stripe`
at the very same time we reserve `first_row_number`, i.e. when writing
the first row to the current `WriteState`.
ii) At flush time, do the storage level allocation and complete the
missing fields of the dummy record inserted into `columnar.stripe`
during i).
That way, any concurrent writes would be able to check against possible
constraint violations by using `SnapshotDirty` when scanning
`columnar.stripe`.
Note that `columnar_fetch_index_tuple` still wouldn't be able to fill
the output tupleslot for the requested tid but it would at least return
`true` for such index look-up's and we believe this should be sufficient
for the caller indexAM callback to make the concurrent writer block on
prior one.
That is how we fix#5160.
Only downside of reserving `stripe_id` at the same time we reserve
`first_row_number` is that now any aborted writes would also waste
some amount of `stripe_id` as in the case of `first_row_number` but
we are just wasting them one-by-one.
Considering the fact that we waste `first_row_number` by the amount
stripe row limit (=150k by default) in such cases, this shouldn't be
important at all.
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)
```
In next commit, we will adjust curcid of the snapshot being used when
scanning the columnar table.
However, for index scan, snapshot is provided not when beginning scan
but within fetch-tuple call.
For this reason, start flushing pending writes in init_columnar_read_state
since this seem to be a prerequisite step that needs to be done before
scanning a columnar table regardless of the scan method being used.
Seems that we always increment the command counter right after
finishing metadata table modification.
For this reason, it makes sense to call CommandCounterIncrement
within FinishModifyRelation.
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.
`tcp_user_timeout` is the awesome relatively unknown big brother of the
TCP keepalive related options. Instead of depending on keepalives being
sent, this determines that a socket is dead by waiting at most N seconds
for an ack of data that it has sent. It's exposed in libpq starting from
PG12.
DESCRIPTION: Fix a segfault caused by use after free in ConnectionsPlacementHash
Fix a segfault caused by retaining data in any of the hashmaps making up the Placement Connection Management.
We have seen production systems segfault due to random data referenced from ConnectionPlacementHash.
On investigation we found that the backends segfaulting on this had OOM errors closely prior to the segfault.
It has shown there are at least 15 places where an allocation can OOM that would cause ConnectionPlacementHash to retain pointers to memory from contexts that are subsequently freed. This would reproduce the segfault we have observed in production.
Conditions for these allocations are:
- allocated after first call to `AssociatePlacementWithShard`: https://github.com/citusdata/citus/blob/v10.0.3/src/backend/distributed/connection/placement_connection.c#L880-L881
- allocated before `StartNodeUserDatabaseConnection`: https://github.com/citusdata/citus/blob/v10.0.3/src/backend/distributed/connection/connection_management.c#L291
At least 15 points of memory allocation (which could fail) are between the callsites of both in a primary key lookup on a reference table - where we have seen an OOM cause a segfault moments later.
Instead of leaving any references in ConnectionPlacementHash, ConnectionShardHash and ColocatedPlacementsHash that could retain any pointers that are freed due to the TopTransactionContext being reset we clear all these hashes irregardless of the state of CurrentCoordinatedTransactionState.
Downside is that on any transaction abort we will now iterate through 4 hashmaps and clear their contents. Given that they are either already empty, which should cause a quick iteration, or non-empty, causing segfaults in subsequent executions, this overhead seems reasonable.
A better solution would be to move the creation of these hashmaps so they would live in the TopTransactionContext themself, assuming their contents would never outlive a transaction. This needs more investigation and is an involved refactor Hence fixing this quickly here.
All the callers except columnar_relation_copy_for_cluster were already
switching to right memory context when creating ColumnarReadState.
With this commit, we embed that logic into init_columnar_read_state
to avoid further such bugs.
That way, we start using the right memory context for
columnar_relation_copy_for_cluster too.
- 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)
Jelte Fennema
Burak Velioglu
Onur Tirtir
jeff-davis
Halil Ozan Akgul
Sait Talha Nisanci
Ahmet Gedemenli
Onder Kalaci
Naisila Puka
Hanefi Onaldi
Nils Dijk