DESCRIPTION: Adds support for propagating `CREATE`/`DROP` database
In this PR, create and drop database support is added.
For CREATE DATABASE:
* "oid" option is not supported
* specifying "strategy" to be different than "wal_log" is not supported
* specifying "template" to be different than "template1" is not
supported
The last two are because those are not saved in `pg_database` and when
activating a node, we cannot assume what parameters were provided when
creating the database.
And "oid" is not supported because whether user specified an arbitrary
oid when creating the database is not saved in pg_database and we want
to avoid from oid collisions that might arise from attempting to use an
auto-assigned oid on workers.
Finally, in case of node activation, GRANTs for the database are also
propagated.
---------
Co-authored-by: Jelte Fennema-Nio <github-tech@jeltef.nl>
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
We propagate `SECURITY LABEL [for provider] ON ROLE rolename IS
labelname` to the worker nodes.
We also make sure to run the relevant `SecLabelStmt` commands on a
newly added node by looking at roles found in `pg_shseclabel`.
See official docs for explanation on how this command works:
https://www.postgresql.org/docs/current/sql-security-label.html
This command stores the role label in the `pg_shseclabel` catalog table.
This commit also fixes the regex string in
`check_gucs_are_alphabetically_sorted.sh` script such that it escapes
the dot. Previously it was looking for all strings starting with "citus"
instead of "citus." as it should.
To test this feature, I currently make use of a special GUC to control
label provider registration in PG_init when creating the Citus extension.
DESCRIPTION: Adds support from issuing role management commands from worker nodes
It's unlikely to get into a distributed deadlock with role commands, we
don't care much about them at the moment.
There were several attempts to reduce the chances of a deadlock but we
didn't any of them merged into main branch yet, see:
#7325#7016#7009
DESCRIPTION: Adds support for ALTER DATABASE <db_name> SET .. statement
propagation
SET statements in Postgres has a common structure which is already being
used in Alter Function
statement.
In this PR, I added a util file; citus_setutils and made it usable for
both for
alter database<db_name>set .. and alter function ... set ... statements.
With this PR, below statements will be propagated
```sql
ALTER DATABASE name SET configuration_parameter { TO | = } { value | DEFAULT }
ALTER DATABASE name SET configuration_parameter FROM CURRENT
ALTER DATABASE name RESET configuration_parameter
ALTER DATABASE name RESET ALL
```
Additionally, there was a bug in processing float values in the common
code block.
I fixed this one as well
Previous
```C
case T_Float:
{
appendStringInfo(buf, " %s", strVal(value));
break;
}
```
Now
```C
case T_Float:
{
appendStringInfo(buf, " %s", nodeToString(value));
break;
}
```
DESCRIPTION: Adds ALTER DATABASE WITH ... and REFRESH COLLATION VERSION
support
This PR adds supports for basic ALTER DATABASE statements propagation
support. Below statements are supported:
ALTER DATABASE <database_name> with IS_TEMPLATE <true/false>;
ALTER DATABASE <database_name> with CONNECTION LIMIT <integer_value>;
ALTER DATABASE <database_name> REFRESH COLLATION VERSION;
---------
Co-authored-by: Jelte Fennema-Nio <jelte.fennema@microsoft.com>
We currently don't support propagating these options in Citus
Relevant PG commits:
https://github.com/postgres/postgres/commit/e3ce2dehttps://github.com/postgres/postgres/commit/3d14e17
Limitation:
We also need to take care of generated GRANT statements by dependencies
in attempt to distribute something else. Specifically, this part of the
code in `GenerateGrantRoleStmtsOfRole`:
```
grantRoleStmt->admin_opt = membership->admin_option;
```
In PG16, membership also has `inherit_option` and `set_option` which
need to properly be part of the `grantRoleStmt`. We can skip for now
since #7164 will take care of this soon, and also this is not an
expected use-case.
Add citus_schema_move() that can be used to move tenant tables within a distributed
schema to another node. The function has two variations as simple wrappers around
citus_move_shard_placement() and citus_move_shard_placement_with_nodeid() respectively.
They pick a shard that belongs to the given tenant schema and resolve the source node
that contain the shards under given tenant schema. Hence their signatures are quite
similar to underlying functions:
```sql
-- citus_schema_move(), using target node name and node port
CREATE OR REPLACE FUNCTION pg_catalog.citus_schema_move(
schema_id regnamespace,
target_node_name text,
target_node_port integer,
shard_transfer_mode citus.shard_transfer_mode default 'auto')
RETURNS void
LANGUAGE C STRICT
AS 'MODULE_PATHNAME', $$citus_schema_move$$;
-- citus_schema_move(), using target node id
CREATE OR REPLACE FUNCTION pg_catalog.citus_schema_move(
schema_id regnamespace,
target_node_id integer,
shard_transfer_mode citus.shard_transfer_mode default 'auto')
RETURNS void
LANGUAGE C STRICT
AS 'MODULE_PATHNAME', $$citus_schema_move_with_nodeid$$;
```
Since in PG16, truncate triggers are supported on foreign tables, we add
the citus_truncate_trigger to Citus foreign tables as well, such that the TRUNCATE
command is propagated to the table's single local shard as well.
Note that TRUNCATE command was working for foreign tables even before this
commit: see https://github.com/citusdata/citus/pull/7170#issuecomment-1706240593 for details
This commit also adds tests with user-enabled truncate triggers on Citus foreign tables:
both trigger on the shell table and on its single foreign local shard.
Relevant PG commit:
https://github.com/postgres/postgres/commit/3b00a94
**Problem:**
Previously we always used an outside superuser connection to overcome
permission issues for the current user while propagating dependencies.
That has mainly 2 problems:
1. Visibility issues during dependency propagation, (metadata connection
propagates some objects like a schema, and outside transaction does not
see it and tries to create it again)
2. Security issues (it is preferrable to use current user's connection
instead of extension superuser)
**Solution (high level):**
Now, we try to make a smarter decision on whether should we use an
outside superuser connection or current user's metadata connection. We
prefer using current user's connection if any of the objects, which is
already propagated in the current transaction, is a dependency for a
target object. We do that since we assume if current user has
permissions to create the dependency, then it can most probably
propagate the target as well.
Our assumption is expected to hold most of the times but it can still be
wrong. In those cases, transaction would fail and user should set the
GUC `citus.create_object_propagation` to `deferred` to work around it.
**Solution:**
1. We track all objects propagated in the current transaction (we can
handle subtransactions),
2. We propagate dependencies via the current user's metadata connection
if any dependency is created in the current transaction to address
issues listed above. Otherwise, we still use an outside superuser
connection.
DESCRIPTION: Fixes some object propagation errors seen with transaction
blocks.
Fixes https://github.com/citusdata/citus/issues/6614
---------
Co-authored-by: Nils Dijk <nils@citusdata.com>
For a database that does not create the citus extension by running
` CREATE EXTENSION citus;`
`CitusHasBeenLoaded ` function ends up querying the `pg_extension` table
every time it is invoked. This is not an ideal situation for a such a
database.
The idea in this PR is as follows:
### A new field in MetadataCache.
Add a new variable `extensionCreatedState `of the following type:
```
typedef enum ExtensionCreatedState
{
UNKNOWN = 0,
CREATED = 1,
NOTCREATED = 2,
} ExtensionCreatedState;
```
When the MetadataCache is invalidated, `ExtensionCreatedState` will be
set to UNKNOWN.
### Invalidate MetadataCache when CREATE/DROP/ALTER EXTENSION citus
commands are run.
- Register a callback function, named
`InvalidateDistRelationCacheCallback`, for relcache invalidation during
the shared library initialization for `citus.so`. This callback function
is invoked in all the backends whenever the relcache is invalidated in
one of the backends. (This could be caused many DDLs operations).
- In the cache invalidation callback,`
InvalidateDistRelationCacheCallback`, invalidate `MetadataCache` zeroing
it out.
- In `CitusHasBeenLoaded`, perform the costly citus is loaded check only
if the `MetadataCache` is not valid.
### Downsides
Any relcache invalidation (caused by various DDL operations) will case
Citus MetadataCache to get invalidated. Most of the time it will be
unnecessary. But we rely on that DDL operations on relations will not be
too frequent.
If we're in the middle of a table type conversion (such as from Citus
local table to a reference table), the table might not have all the
placements that we expect from the table type. For this reason, we
should intersect the placements of tables at hand when creating
inter-shard ddl tasks.
DESCRIPTION: Adds grant/revoke propagation support for database
privileges
Following the implementation of support for granting and revoking
database privileges, certain tests that issued grants for worker nodes
experienced failures. These ones are fixed in this PR as well.
DESCRIPTION: Adds PG16Beta3 support
This is the final commit that adds
PG16 compatibility with Citus's current features.
You can use Citus community with PG16Beta3. This commit:
- Enables PG16 in the configure script.
- Adds PG16 tests to CI using test images that have 16beta3
- Skips wal2json cdc test since wal2json package is not available for PG16 yet
- Fixes an isolation test
Several PG16 Compatibility commits have been merged before this final one.
All these subtasks are done https://github.com/citusdata/citus/issues/7017
See the list below:
1 - 42d956888d
Resolve compilation issues
2 - 0d503dd5ac
Ruleutils and successful CREATE EXTENSION
3 - 907d72e60d
Some test outputs
4 - 7c6b4ce103
Outer join checks, subscription password, crash fixes
5 - 6056cb2c29
get_relation_info hook to avoid crash from adjusted partitioning
6 - b36c431abb
Rework PlannedStmt and Query's Permission Info
7 - ee3153fe50
More test output fixes
8 - 2c50b5f7ff
varnullingrels additions
9 - b2291374b4
More test output fixes
10- a2315fdc67
New options to vacuum and analyze
11- 9fa72545e2
Fix AM dependency and grant's admin option
12- 2d6cf8e79a
One more outer join check
Stay tuned for PG16 new features in Citus :)
PG16 compatibility - part 11
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
part 9 b2291374b4
part 10 a2315fdc67
This commit is in the series of PG16 compatibility commits. It fixes
AM dependency and grant's admin option:
- Fix with admin option in grants
grantstmt->admin_opt no longer exists in PG16
instead, grantstmt has a list of options, one of them is admin option.
Relevant PG commit:
e3ce2de09d
e3ce2de09d814f8770b2e3b3c152b7671bcdb83f
- Fix pg_depend entry to AMs after ALTER TABLE .. SET ACCESS METHOD
Relevant PG commit:
97d8910104
97d89101045fac8cb36f4ef6c08526ea0841a596
More PG16 compatibility commits are coming soon:
We are very close to merging "PG16Beta3 Support - Regression tests sanity"
PG16 compatibility - part 10
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
part 9 b2291374b4
This commit is in the series of PG16 compatibility commits. It:
- Adds buffer_usage_limit to vacuum and analyze
- Adds process_main, skip_database_stats, only_database_stats to vacuum
Important Note: adding these options is actually required for check-vanilla tests to succeed.
However, in concept, this PR belongs to "PG16 new features",
rather than "PG16 regression tests sanity"
Relevant PG commits:
1cbbee0338
1cbbee03385763b066ae3961fc61f2cd01a0d0d7
4211fbd841
4211fbd8413b26e0abedbe4338aa7cda2cd469b4
a46a7011b2
a46a7011b27188af526047a111969f257aaf4db8
More PG16 compatibility commits are coming soon ...
This PR provides successful compilation against PG16Beta2. It does some
necessary refactoring to prepare for full support of version 16, in
https://github.com/citusdata/citus/pull/6952 .
Change RelFileNode to RelFileNumber or RelFileLocator
Relevant PG commit
b0a55e43299c4ea2a9a8c757f9c26352407d0ccc
new header for varatt.h
Relevant PG commit:
d952373a987bad331c0e499463159dd142ced1ef
drop support for Abs, use fabs
Relevant PG commit
357cfefb09115292cfb98d504199e6df8201c957
tuplesort PGcommit: d37aa3d35832afde94e100c4d2a9618b3eb76472
Relevant PG commit:
d37aa3d35832afde94e100c4d2a9618b3eb76472
Fix vacuum in columnar
Relevant PG commit:
4ce3afb82ecfbf64d4f6247e725004e1da30f47c
older one:
b6074846cebc33d752f1d9a66e5a9932f21ad177
Add alloc_flags to pg_clean_ascii
Relevant PG commit:
45b1a67a0fcb3f1588df596431871de4c93cb76f
Merge GetNumConfigOptions() into get_guc_variables()
Relevant PG commit:
3057465acfbea2f3dd7a914a1478064022c6eecd
Minor PG refactor PG_FUNCNAME_MACRO __func__
Relevant PG commit
320f92b744b44f961e5d56f5f21de003e8027a7f
Pass NULL context to stringToQualifiedNameList, typeStringToTypeName
The pre-PG16 error behaviour for the following
stringToQualifiedNameList & typeStringToTypeName
was ereport(ERROR, ...)
Now with PG16 we have this context input. We preserve the same behaviour
by passing a NULL context, because of the following:
(copy paste comment from PG16)
If "context" isn't an ErrorSaveContext node, this behaves as
errstart(ERROR, domain), and the errsave() macro ends up acting
exactly like ereport(ERROR, ...).
Relevant PG commit
858e776c84f48841e7e16fba7b690b76e54f3675
Use RangeVarCallbackMaintainsTable instead of RangeVarCallbackOwnsTable
Relevant PG commit:
60684dd834a222fefedd49b19d1f0a6189c1632e
FIX THIS: Not implemented grant-level control of role inheritance
see PG commit
e3ce2de09d814f8770b2e3b3c152b7671bcdb83f
Make Scan node abstract
PG commit:
8c73c11a0d39049de2c1f400d8765a0eb21f5228
Change in Var representations, get_relids_in_jointree
PG commit
2489d76c4906f4461a364ca8ad7e0751ead8aa0d
Deadlock detection changes because SHM_QUEUE is removed
Relevant PG Commit:
d137cb52cb7fd44a3f24f3c750fbf7924a4e9532
TU_UpdateIndexes
Relevant PG commit
19d8e2308bc51ec4ab993ce90077342c915dd116
Use object_ownercheck and object_aclcheck functions
Relevant PG commits:
afbfc02983f86c4d71825efa6befd547fe81a926
c727f511bd7bf3c58063737bcf7a8f331346f253
Rework Permission Info for successful compilation
Relevant PG commits:
postgres/postgres@a61b1f7postgres/postgres@b803b7d
---------
Co-authored-by: onderkalaci <onderkalaci@gmail.com>
Index scans in PG16 return empty sets because of extra compatibility
enforcement for `ScanKeyInit` arguments.
Could be one of the relevant PG commits:
c8b2ef05f4
This PR fixes all incompatible `RegProcedure` and `Datum` arguments in
all `ScanKeyInit` functions used throughout the codebase.
Helpful for https://github.com/citusdata/citus/pull/6952
We allow materialized view to exist in distrbuted schema but they should
not be tried to be converted to a tenant table since they cannot be
distributed.
Fixes https://github.com/citusdata/citus/issues/7041
Inserting into `pg_dist_schema` causes unexpected duplicate key errors,
for distributed schemas that already exist. With this commit we skip the
insertion if the schema already exists in `pg_dist_schema`.
The error:
```sql
SET citus.enable_schema_based_sharding TO ON;
CREATE SCHEMA sc2;
CREATE SCHEMA IF NOT EXISTS sc2;
NOTICE: schema "sc2" already exists, skipping
ERROR: duplicate key value violates unique constraint "pg_dist_schema_pkey"
DETAIL: Key (schemaid)=(17294) already exists.
```
fixes: #7042
This commit is the second and last phase of dropping PG13 support.
It consists of the following:
- Removes all PG_VERSION_13 & PG_VERSION_14 from codepaths
- Removes pg_version_compat entries and columnar_version_compat entries
specific for PG13
- Removes alternative pg13 test outputs
- Removes PG13 normalize lines and fix the test outputs based on that
It is a continuation of 5bf163a27d
Fixes a bug related to `CREATE SCHEMA AUTHORIZATION <rolename>` for single shard
tables. We should properly fetch schema name from role specification if schema name is not given.
We need to rewind the tuplestorestate's tuple index to get correct
results on fetching scrollable with hold cursors.
`PersistHoldablePortal` is responsible for persisting out
tuplestorestate inside a with hold cursor before commiting a
transaction.
It rewinds the cursor like below (`ExecutorRewindcalls` calls `rescan`):
```c
if (portal->cursorOptions & CURSOR_OPT_SCROLL)
{
ExecutorRewind(queryDesc);
}
```
At the end, it adjusts tuple index for holdStore in the portal properly.
```c
if (portal->cursorOptions & CURSOR_OPT_SCROLL)
{
if (!tuplestore_skiptuples(portal->holdStore,
portal->portalPos,
true))
elog(ERROR, "unexpected end of tuple stream");
}
```
DESCRIPTION: Fixes incorrect results on fetching scrollable with hold
cursors.
Fixes https://github.com/citusdata/citus/issues/7010
1) For distributed tables that are not colocated.
2) When joining on a non-distribution column for colocated tables.
3) When merging into a distributed table using reference or citus-local tables as the data source.
This is accomplished primarily through the implementation of the following two strategies.
Repartition: Plan the source query independently,
execute the results into intermediate files, and repartition the files to
co-locate them with the merge-target table. Subsequently, compile a final
merge query on the target table using the intermediate results as the data
source.
Pull-to-coordinator: Execute the plan that requires evaluation at the coordinator,
run the query on the coordinator, and redistribute the resulting rows to ensure
colocation with the target shards. Direct the MERGE SQL operation to the worker
nodes' target shards, using the intermediate files colocated with the data as the
data source.
Adds support for altering schema of single shard tables. We do that in 2
steps.
1. Undistribute the tenant table at `preprocess` step,
2. Distribute new schema if it is a distributed schema after DDLs are
propagated.
DESCRIPTION: Adds support for altering a table's schema to/from
distributed schemas.
Allow using generated identity column based on int/smallint when
creating a distributed table so that applications that rely on
those data types don't break.
Inserting into / modifying such columns from workers is not allowed
but it's better than not allowing such columns altogether.
PG16beta1 added some sanity checks for GUCS, find the Relevant PG
commits below:
1- Add check on initial and boot values when loading GUCs
a73952b795
2- Extend check_GUC_init() with checks on flag combinations when loading
GUCs
009f8d1714
I fixed our currently problematic GUCS, we can merge this directly into
main as these make sense for any PG version.
There was a particular NodeConninfo issue:
Previously we would rely on the fact that NodeConninfo initial value
is an empty string. However, with PG16 enforcing same initial and boot
values, we can't use an empty initial value for NodeConninfo anymore.
Therefore we add a new flag to indicate whether we are at boot check.
* Currently we do not allow any Citus tables other than Citus local
tables inside a regular schema before executing
`citus_schema_distribute`.
* `citus_schema_undistribute` expects only single shard distributed
tables inside a tenant schema.
DESCRIPTION: Adds the udf `citus_schema_distribute` to convert a regular
schema into a tenant schema.
DESCRIPTION: Adds the udf `citus_schema_undistribute` to convert a
tenant schema back to a regular schema.
---------
Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
PG16 removed them. They were already identical to Assert. We can merge
this directly to main branch
Relevant PG commit:
b1099eca8f
b1099eca8f38ff5cfaf0901bb91cb6a22f909bc6
Co-authored-by: onderkalaci <onderkalaci@gmail.com>
Verify Citus UDFs work well with single shard tables
SUPPORTED
* citus_table_size
* citus_total_relation_size
* citus_relation_size
* citus_shard_sizes
* truncate_local_data_after_distributing_table
* create_distributed_function // test function colocated with a single
shard table
* undistribute_table
* alter_table_set_access_method
UNSUPPORTED - error out for single shard tables
* master_create_empty_shard
* create_distributed_table_concurrently
* create_distributed_table
* create_reference_table
* citus_add_local_table_to_metadata
* citus_split_shard_by_split_points
* alter_distributed_table
DESCRIPTION: Adds citus.enable_schema_based_sharding GUC that allows
sharding the database based on schemas when enabled.
* Refactor the logic that automatically creates Citus managed tables
* Refactor CreateSingleShardTable() to allow specifying colocation id
instead
* Add support for schema-based-sharding via a GUC
### What this PR is about:
Add **citus.enable_schema_based_sharding GUC** to enable schema-based
sharding. Each schema created while this GUC is ON will be considered
as a tenant schema. Later on, regardless of whether the GUC is ON or
OFF, any table created in a tenant schema will be converted to a
single shard distributed table (without a shard key). All the tenant
tables that belong to a particular schema will be co-located with each
other and will have a shard count of 1.
We introduce a new metadata table --pg_dist_tenant_schema-- to do the
bookkeeping for tenant schemas:
```sql
psql> \d pg_dist_tenant_schema
Table "pg_catalog.pg_dist_tenant_schema"
┌───────────────┬─────────┬───────────┬──────────┬─────────┐
│ Column │ Type │ Collation │ Nullable │ Default │
├───────────────┼─────────┼───────────┼──────────┼─────────┤
│ schemaid │ oid │ │ not null │ │
│ colocationid │ integer │ │ not null │ │
└───────────────┴─────────┴───────────┴──────────┴─────────┘
Indexes:
"pg_dist_tenant_schema_pkey" PRIMARY KEY, btree (schemaid)
"pg_dist_tenant_schema_unique_colocationid_index" UNIQUE, btree (colocationid)
psql> table pg_dist_tenant_schema;
┌───────────┬───────────────┐
│ schemaid │ colocationid │
├───────────┼───────────────┤
│ 41963 │ 91 │
│ 41962 │ 90 │
└───────────┴───────────────┘
(2 rows)
```
Colocation id column of pg_dist_tenant_schema can never be NULL even
for the tenant schemas that don't have a tenant table yet. This is
because, we assign colocation ids to tenant schemas as soon as they
are created. That way, we can keep associating tenant schemas with
particular colocation groups even if all the tenant tables of a tenant
schema are dropped and recreated later on.
When a tenant schema is dropped, we delete the corresponding row from
pg_dist_tenant_schema. In that case, we delete the corresponding
colocation group from pg_dist_colocation as well.
### Future work for 12.0 release:
We're building schema-based sharding on top of the infrastructure that
adds support for creating distributed tables without a shard key
(https://github.com/citusdata/citus/pull/6867).
However, not all the operations that can be done on distributed tables
without a shard key necessarily make sense (in the same way) in the
context of schema-based sharding. For example, we need to think about
what happens if user attempts altering schema of a tenant table. We
will tackle such scenarios in a future PR.
We will also add a new UDF --citus.schema_tenant_set() or such-- to
allow users to use an existing schema as a tenant schema, and another
one --citus.schema_tenant_unset() or such-- to stop using a schema as
a tenant schema in future PRs.
We mark objects as distributed objects in Citus metadata only if we need
to propagate given the command that creates it to worker nodes. For this
reason, we were not doing this for the objects that are created while
pg_dist_node is empty.
One implication of doing so is that we defer the schema propagation to
the time when user creates the first distributed table in the schema.
However, this doesn't help for schema-based sharding (#6866) because we
want to sync pg_dist_tenant_schema to the worker nodes even for empty
schemas too.
* Support test dependencies for isolation tests without a schedule
* Comment out a test due to a known issue (#6901)
* Also, reduce the verbosity for some log messages and make some
tests compatible with run_test.py.
Add tests for ddl coverage:
* indexes
* partitioned tables + indexes with long names
* triggers
* foreign keys
* statistics
* grant & revoke statements
* truncate & vacuum
* create/test/drop view that depends on a dist table with no shard key
* policy & rls test
* alter table add/drop/alter_type column (using sequences/different data
types/identity columns)
* alter table add constraint (not null, check, exclusion constraint)
* alter table add column with a default value / set default / drop
default
* alter table set option (autovacuum)
* indexes / constraints without names
* multiple subcommands
Adds support for
* Creating new partitions after distributing (with null key) the parent
table
* Attaching partitions to a distributed table with null distribution key
(and automatically distribute the new partition with null key as well)
* Detaching partitions from it
With this PR, we allow creating distributed tables with without
specifying a shard key via create_distributed_table(). Here are the
the important details about those tables:
* Specifying `shard_count` is not allowed because it is assumed to be 1.
* We mostly call such tables as "null shard-key" table in code /
comments.
* To avoid doing a breaking layout change in create_distributed_table();
instead of throwing an error, it will inform the user that
`distribution_type`
param is ignored unless it's explicitly set to NULL or 'h'.
* `colocate_with` param allows colocating such null shard-key tables to
each other.
* We define this table type, i.e., NULL_SHARD_KEY_TABLE, as a subclass
of
DISTRIBUTED_TABLE because we mostly want to treat them as distributed
tables in terms of SQL / DDL / operation support.
* Metadata for such tables look like:
- distribution method => DISTRIBUTE_BY_NONE
- replication model => REPLICATION_MODEL_STREAMING
- colocation id => **!=** INVALID_COLOCATION_ID (distinguishes from
Citus local tables)
* We assign colocation groups for such tables to different nodes in a
round-robin fashion based on the modulo of "colocation id".
Note that this PR doesn't care about DDL (except CREATE TABLE) / SQL /
operation (i.e., Citus UDFs) support for such tables but adds a
preliminary
API.
We need to break sequence dependency for a table while creating the
table during non-transactional metadata sync to ensure idempotency of
the creation of the table.
**Problem:**
When we send `SELECT
pg_catalog.worker_drop_sequence_dependency(logicalrelid::regclass::text)
FROM pg_dist_partition` to workers during the non-transactional sync,
table might not be in `pg_dist_partition` at worker, and sequence
dependency is not broken at the worker.
**Solution:**
We break sequence dependency via `SELECT
pg_catalog.worker_drop_sequence_dependency(logicalrelid::regclass::text)`
for each table while creating it at the workers. It is safe to send
since the udf is a no-op when there is no sequence dependency.
DESCRIPTION: Fixes a bug related to sequence idempotency at
non-transactional sync.
Fixes https://github.com/citusdata/citus/issues/6888.
.. rather than having it in user facing functions. That way, we
can use the same logic for creating Citus tables from other places
too.
This would be useful for creating tenant tables via a simple function
call in the utility hook, for schema-based sharding purposes.
Add new metadata sync methods which uses MemorySyncContext api so that during the sync we can
- free memory to prevent OOM,
- use either transactional or nontransactional modes according to the GUC .
This pull request proposes a change to the logic used for propagating
identity columns to worker nodes in citus. Instead of creating a
dependent sequence for each identity column and changing its default
value to `nextval(seq)/worker_nextval(seq)`, this update will pass the
identity columns as-is to the worker nodes.
Please note that there are a few limitations to this change.
1. Only bigint identity columns will be allowed in distributed tables to
ensure compatibility with the DDL from any node functionality. Our
current distributed sequence implementation only allows insert
statements from all nodes for bigint sequences.
2. `alter_distributed_table` and `undistribute_table` operations will
not be allowed for tables with identity columns. This is because we do
not have a proper way of keeping sequence states consistent across the
cluster.
DESCRIPTION: Prevents using identity columns on data types other than
`bigint` on distributed tables
DESCRIPTION: Prevents using `alter_distributed_table` and
`undistribute_table` UDFs when a table has identity columns
DESCRIPTION: Fixes a bug that prevents enforcing identity column
restrictions on worker nodes
Depends on #6740Fixes#6694
Description:
Implementing CDC changes using Logical Replication to avoid
re-publishing events multiple times by setting up replication origin
session, which will add "DoNotReplicateId" to every WAL entry.
- shard splits
- shard moves
- create distributed table
- undistribute table
- alter distributed tables (for some cases)
- reference table operations
The citus decoder which will be decoding WAL events for CDC clients,
ignores any WAL entry with replication origin that is not zero.
It also maps the shard names to distributed table names.
Decide core distribution params in CreateCitusTable to reduce the
chances of
creating Citus tables based on incorrect combinations of distribution
method
and replication model params.
Also introduce DistributedTableParams struct to encapsulate the
parameters
that are specific to distributed tables.
Now that we will soon add another table type having DISTRIBUTE_BY_NONE
as distribution method and that we want the code to interpret such
tables mostly as distributed tables, let's make the definition of those
other two table types more strict by removing
CITUS_TABLE_WITH_NO_DIST_KEY
macro.
And instead, use HasDistributionKey() check in the places where the
logic applies to all table types that have / don't have a distribution
key. In future PRs, we might want to convert some of those
HasDistributionKey() checks if logic only applies to Citus local /
reference tables, not the others.
And adding HasDistributionKey() also allows us to consider having
DISTRIBUTE_BY_NONE as the distribution method as a "table attribute"
that can apply to distributed tables too, rather something that
determines the table type.
Split the main logic that allows creating a Citus table into the
internal function CreateCitusTable().
Old CreateDistributedTable() function was assuming that it's creating
a reference table when the distribution method is DISTRIBUTE_BY_NONE.
However, soon this won't be the case when adding support for creating
single-shard distributed tables because their distribution method would
also be the same.
Now the internal method CreateCitusTable() doesn't make any assumptions
about table's replication model or such. Instead, it expects callers to
properly set all such metadata bits.
Even more, some of the parameters the old CreateDistributedTable() takes
--such as the shard count-- were not meaningful for a reference table,
and would be the same as for new table type.
2 improvements to prevent memory leaks during altering or undistributing
distributed tables with a lot of partitions and shards:
1. Free memory for each call to ConvertTable so that colocated and partition tables at
`AlterDistributedTable`, `UndistributeTable`, or
`AlterTableSetAccessMethod` will not cause an increase
in memory usage,
2. Free memory while executing attach partition commands for each partition table at
`AlterDistributedTable` to prevent an increase in memory usage.
DESCRIPTION: Fixes memory leak issue during altering distributed table
with a lot of partition and shards.
Fixes https://github.com/citusdata/citus/issues/6503.
We have memory leak during distribution of a table with a lot of
partitions as we do not release memory at ExprContext until all
partitions are not distributed. We improved 2 things to resolve the
issue:
1. We create and delete MemoryContext for each call to
`CreateDistributedTable` by partitions,
2. We rebuild the cache after we insert all the placements instead of
each placement for a shard.
DESCRIPTION: Fixes memory leak during distribution of a table with a lot
of partitions and shards.
Fixes https://github.com/citusdata/citus/issues/6572.
Prevents memory leak during ConvertTable call for a table with a lot of
partitions.
DESCRIPTION: Fixes memory leak during undistribution and alteration of a
table with a lot of partitions.
We should disallow dropping table_name option if foreign table is in
metadata. Otherwise, we get table not found error which contains
shardid.
DESCRIPTION: Fixes an unexpected foreign table error by disallowing to drop the table_name option.
Fixes#6663
DESCRIPTION: Fix foreign key validation skip at the end of shard move
In eadc88a we started completely skipping foreign key constraint
validation at the end of a non blocking shard move, instead of only for
foreign keys to reference tables. However, it turns out that this didn't
work at all because of a hard to notice bug: By resetting the
SkipConstraintValidation flag at the end of our utility hook, we
actually make the SET command that sets it a no-op.
This fixes that bug by removing the code that resets it. This is fine
because #6543 removed the only place where we set the flag in C code. So
the resetting of the flag has no purpose anymore. This PR also adds a
regression test, because it turned out we didn't have any otherwise we
would have caught that the feature was completely broken.
It also moves the constraint validation skipping to the utility hook.
The reason is that #6550 showed us that this is the better place to skip
it, because it will also skip the planning phase and not just the
execution.
Fixes#6655.
heap_modify_tuple() fetches values[i] if replace[i] is set true,
regardless of the fact that whether isnull[i] is true or false. So
similar to replace[], let's init values[] & isnull[] too.
DESCRIPTION: Fixes an uninitialized memory access in
create_distributed_function()
This change allows creating a constraint without a name using an index.
The index name will be used as the constraint name the same way postgres
handles it.
Fixes issue #6644
This commit also cleans up some leftovers from nameless constraint checks.
With this commit, we now fully support adding all nameless constraints
directly to a table.
Co-authored-by: naisila <nicypp@gmail.com>
DESCRIPTION: Fix regression in allowed foreign keys on distributed
tables
In commit eadc88a we changed how we skip foreign key validation. The
goal was to skip it in more cases. However, one change had the
unintended regression of introducing failures when trying to create
certain foreign keys. This reverts that part of the change.
The way of skipping validation of foreign keys that was introduced in
eadc88a was skipping validation during execution. The reason that
this caused this regression was because some foreign key validation
queries already fail during planning. In those cases it never gets to
the execution step where it would later be skipped.
Fixes#6543
DESCRIPTION: Enable adding FOREIGN KEY constraints on Citus tables
without a name
This PR enables adding a foreign key to a distributed/reference/Citus
local table without specifying the name of the constraint, e.g. `ALTER
TABLE items ADD FOREIGN KEY (user_id) REFERENCES users (id);`
DESCRIPTION: Enable adding CHECK constraints on distributed tables
without the client having to provide a constraint name.
This PR enables the following command syntax for adding check
constraints to distributed tables.
ALTER TABLE ... ADD CHECK ...
by creating a default constraint name and transforming the command into
the below syntax before sending it to workers.
ALTER TABLE ... ADD CONSTRAINT \<conname> CHECK ...
DESCRIPTION: Adds support for creating table constraints UNIQUE and
EXCLUDE via ALTER TABLE command without client having to specify a name.
ALTER TABLE ... ADD CONSTRAINT <conname> UNIQUE ...
ALTER TABLE ... ADD CONSTRAINT <conname> EXCLUDE ...
commands require the client to provide an explicit constraint name.
However, in postgres it is possible for clients not to provide a name
and let the postgres generate it using the following commands
ALTER TABLE ... ADD UNIQUE ...
ALTER TABLE ... ADD EXCLUDE ...
This PR enables the same functionality for citus tables.
DESCRIPTION: Support ALTER TABLE .. ADD PRIMARY KEY ... command
Before processing
> **ALTER TABLE ... ADD PRIMARY KEY ...**
command
1. Create a primary key name to use as the constraint name.
2. Change the **ALTER TABLE ... ADD PRIMARY KEY ...** command to into
**ALTER TABLE ... ADD CONSTRAINT \<constraint name> PRIMARY KEY ...**
form.
This is the only form we can specify a name for a primary key. If we run
ALTER TABLE .. ADD PRIMARY KEY, postgres
would create a constraint name internally in its own scheme. But the
problem is that we need to create constraint names
for shards in our own scheme which is \<constraint name>_\<shardid>.
Hence we need to create a name and send it to workers so that the
workers can append the shardid.
4. Run the changed command on the coordinator to make sure we are using
the same constraint name across the board.
5. Send the changed command to workers such that it is executed for the
main table as well as for the shards.
Fixes#6515.
DESCRIPTION: Extend cleanup process for replication artifacts
This PR adds new cleanup record types for:
* Subscriptions
* Replication slots
* Publications
* Users created for subscriptions
We add records for these object types, to `pg_dist_cleanup` during
creation phase. Once the operation is done, in case of success or
failure, we iterate those records and drop the objects. With this PR we
will not be dropping any of these objects during the operation. In
short, we will always be deferring the drop.
One thing that's worth mentioning is that we sort cleanup records before
processing (dropping) them, because of dependency relations among those
objects, e.g a subscription might depend on a publication. Therefore, we
always drop subscriptions before publications.
We have some renames in this PR:
* `TryDropOrphanedShards` -> `TryDropOrphanedResources`
* `DropOrphanedShardsForCleanup` -> `DropOrphanedResourcesForCleanup`
* `run_try_drop_marked_shards` -> `run_try_drop_marked_resources`
as these functions now process replication artifacts as well.
This PR drops function `DropAllLogicalReplicationLeftovers` and its all
usages, since now we rely on the deferring drop mechanism.
DESCRIPTION: Makes sure to disallow triggers that depend on extensions
We were already doing so for `ALTER trigger DEPENDS ON EXTENSION`
commands. However, we also need to disallow creating Citus tables
having such triggers already, so this PR fixes that.
This didn't cause any bugs since today we're always calling
UpdateAutoConvertedForConnectedRelations with autoconverted=false, so we
don't need to backport this to anywhere.
Gürkan İndibay
Naisila Puka
Onur Tirtir
Nils Dijk
zhjwpku
aykut-bozkurt
Emel Şimşek
Ahmet Gedemenli
Teja Mupparti
Marco Slot
aykutbozkurt
Gokhan Gulbiz
Marco Slot
rajeshkt78
Jelte Fennema
songjinzhou
Philip Dubé