* Add user-defined sequence support for MX
* Remove default part when propagating to workers
* Fix ALTER TABLE with sequences for mx tables
* Clean up and add tests
* Propagate DROP SEQUENCE
* Removing function parts
* Propagate ALTER SEQUENCE
* Change sequence type before propagation & cleanup
* Revert "Propagate ALTER SEQUENCE"
This reverts commit 2bef64c5a29f4e7224a7f43b43b88e0133c65159.
* Ensure sequence is not used in a different column with different type
* Insert select tests
* Propagate rename sequence stmt
* Fix issue with group ID cache invalidation
* Add ALTER TABLE ALTER COLUMN TYPE .. precaution
* Fix attnum inconsistency and add various tests
* Add ALTER SEQUENCE precaution
* Remove Citus hook
* More tests
Co-authored-by: Marco Slot <marco.slot@gmail.com>
DESCRIPTION: Add support for ALTER DATABASE OWNER
This adds support for changing the database owner. It achieves this by marking the database as a distributed object. By marking the database as a distributed object it will look for its dependencies and order the user creation commands (enterprise only) before the alter of the database owner. This is mostly important when adding new nodes.
By having the database marked as a distributed object it can easily understand for which `ALTER DATABASE ... OWNER TO ...` commands to propagate by resolving the object address of the database and verifying it is a distributed object, and hence should propagate changes of owner ship to all workers.
Given the ownership of the database might have implications on subsequent commands in transactions we force sequential mode for transactions that have a `ALTER DATABASE ... OWNER TO ...` command in them. This will fail the transaction with meaningful help when the transaction already executed parallel statements.
By default the feature is turned off since roles are not automatically propagated, having it turned on would cause hard to understand errors for the user. It can be turned on by the user via setting the `citus.enable_alter_database_owner`.
This commit brings following features:
Foreign key support from citus local tables to reference tables
* Foreign key support from reference tables to citus local tables
(only with RESTRICT & NO ACTION behavior)
* ALTER TABLE ENABLE/DISABLE trigger command support
* CREATE/DROP/ALTER trigger command support
and disallows:
* ALTER TABLE ATTACH/DETACH PARTITION commands
* CREATE TABLE <postgres table> ATTACH PARTITION <citus local table>
commands
* Foreign keys from postgres tables to citus local tables
(the other way was already disallowed)
for citus local tables.
The error message when index has opclassopts is improved and the commit
from postgres side is also included for future reference.
Also some minor style related changes are applied.
Error out if index has opclassopts.
Changelog entry on PG13:
Allow CREATE INDEX to specify the GiST signature length and maximum number of integer ranges (Nikita Glukhov)
This commit mostly adds pg_get_triggerdef_command to our ruleutils_13.
This doesn't add anything extra for ruleutils 13 so it is basically a copy
of the change on ruleutils_12
When there is a join alias, var->varnosync will point to the alias and
var->varno will point to the table itself, but we need to use the alias
when deparsing the query. Hence a workaround is introduced to solve this
problem in ruleutils. Normally this case can be understood with
dpns->plan == NULL check but in our case, dpns->plan is always NULL. We
should sync our ruleutils at some point with postgres ruleutils. This
could be a wrong solution as well but the tests pass.
For joins 3 new fields are added, joinleftcols, joinrightcols, and
joinmergedcols. We are not interested in joinmergedcols because we
always expand the column used in joins. There joinmergedcols is always 0
in our case.
For filling joinleftcols and joinrightcols we basically construct the
lists with sequences so either list is of the form: [1 2 3 4 .... n]
Ruleutils is not completed synced with postgres ruleutils and the most
important part is identify_join_columns function change, which now uses
joinleftcols and joinrightcols.
Commit on postgres side:
9ce77d75c5ab094637cc4a446296dc3be6e3c221
A useful email thread:
https://www.postgresql.org/message-id/flat/7115.1577986646%40sss.pgh.pa.us#0ae1d66feeb400013fbaa67a7cccd6ca
Postgres changed some join related fields and therefore they also
changed ruleutils, this commit applies those changes to our copy of
ruleutils.
Related commit on postgres side:
9ce77d75c5ab094637cc4a446296dc3be6e3c221
With PG13 heap_* (heap_open, heap_close etc) are replaced with table_*
(table_open, table_close etc).
It is better to use the new table access methods in the codebase and
define the macros for the previous versions as we can easily remove the
macro without having to change the codebase when we drop the support for
the old version.
Commits that introduced this change on Postgres:
f25968c49697db673f6cd2a07b3f7626779f1827
e0c4ec07284db817e1f8d9adfb3fffc952252db0
4b21acf522d751ba5b6679df391d5121b6c4a35f
Command to see relevant commits on Postgres side:
git log --all --grep="heap_open"
* ensure propagation of CHECK statements to workers with parantheses & adjust regression test outputs
* add tests for distributing tables with simple CHECK constraints
* added test for CHECK on bool variable
Some GUCs support a list of values which is indicated by GUC_LIST_INPUT flag.
When an ALTER ROLE .. SET statement is executed, the new configuration
default for affected users and databases are stored in the
setconfig(text[]) column in a pg_db_role_setting record.
If a GUC that supports a list of values is used in an ALTER ROLE .. SET
statement, we need to split the text into items delimited by commas.
DESCRIPTION: Force aliases in deparsing for queries with anonymous column references
Fixes: #3985
The root cause has todo with discrepancies in the query tree we create. I think in the future we should spend some time on categorising all changes we made to ruleutils and see if we can change the data structure `query` we pass to the deparser to have an actual valid postgres query for the deparser to render.
For now the fix is to keep track, besides changing the names of the entries in the target list, also if we have a reference to an anonymous columns. If there are anonymous columns we set the `printaliases` flag to true which forces the deparser to add the aliases.
To reduce code duplication, implement function that pushes search_path
to be NIL and sets addCatalog to true so that all objects outside of
pg_catalog will be schema-prefixed.
Append IF NOT EXISTS to CREATE SERVER commands generated by
pg_get_serverdef_string function when deparsing an existing server
object that a foreign table depends.
DESCRIPTION: Alter role only works for citus managed roles
Alter role was implemented before we implemented good role management that hooks into the object propagation framework. This is a refactor of all alter role commands that have been implemented to
- be on by default
- only work for supported roles
- make the citus extension owner a supported role
Instead of distributing the alter role commands for roles at the beginning of the node activation role it now _only_ executes the alter role commands for all users in all databases and in the current database.
In preparation of full role support small refactors have been done in the deparser.
Earlier tests targeting other roles than the citus extension owner have been either slightly changed or removed to be put back where we have full role support.
Fixes#2549
In PostgreSQL, user defaults for config parameters can be changed by
ALTER ROLE .. SET statements. We wish to propagate those defaults
accross the Citus cluster so that the behaviour will be similar in
different workers.
The defaults can either be set in a specific database, or the whole
cluster, similarly they can be set for a single role or all roles.
We propagate the ALTER ROLE .. SET if all the conditions below are met:
- The query affects the current database, or all databases
- The user is already created in worker nodes
DESCRIPTION: satisfy static analysis tool for a nullptr dereference
During the static analysis project on the codebase this code has been flagged as having the potential for a null pointer dereference. Funnily enough the author had already made a comment of it in the code this was not possible due to us setting the schema name before we pass in the statement. If we want to reuse this code in a later setting this comment might not always apply and we could actually run into null pointer dereference.
This patch changes a bit of the code around to first of all make sure there is no NULL pointer dereference in this code anymore.
Secondly we allow for better deparsing by setting and adhering to the `if_not_exists` flag on the statement.
And finally add support for all syntax described in the documentation of postgres (FROM was missing).
Comparison between differently sized integers in loop conditions can cause
infinite loops. This can happen when doing something like this:
```c
int64 very_big = MAX_INT32 + 1;
for (int32 i = 0; i < very_big; i++) {
// do something
}
// never reached because i overflows before it can reach the value of very_big
```
In two places I've made code more straight forward by using ROUTINE in our own codegen
Two changes which may seem extraneous:
AppendFunctionName was updated to not use pg_get_function_identity_arguments.
This is because that function includes ORDER BY when printing an aggregate like my_rank.
While ALTER AGGREGATE my_rank(x "any" ORDER BY y "any") is accepted by postgres,
ALTER ROUTINE my_rank(x "any" ORDER BY y "any") is not.
Tests were updated to use macaddr over integer. Using integer is flaky, our logic
could sometimes end up on tables like users_table. I originally wanted to use money,
but money isn't hashable.
DESCRIPTION: Disallow distributed functions for functions depending on an extension
Functions depending on an extension cannot (yet) be distributed by citus. If we would allow this it would cause issues with our dependency following mechanism as we stop following objects depending on an extension.
By not allowing functions to be distributed when they depend on an extension as well as not allowing to make distributed functions depend on an extension we won't break the ability to add new nodes. Allowing functions depending on extensions to be distributed at the moment could cause problems in that area.
DESCRIPTION: Propagate CREATE OR REPLACE FUNCTION
Distributed functions could be replaced, which should be propagated to the workers to keep the function in sync between all nodes.
Due to the complexity of deparsing the `CreateFunctionStmt` we actually produce the plan during the processing phase of our utilityhook. Since the changes have already been made in the catalog tables we can reuse `pg_get_functiondef` to get us the generated `CREATE OR REPLACE` sql.
DESCRIPTION: Propagate ALTER FUNCTION statements for distributed functions
Using the implemented deparser for function statements to propagate changes to both functions and procedures that are previously distributed.
This PR aims to add all the necessary logic to qualify and deparse all possible `{ALTER|DROP} .. {FUNCTION|PROCEDURE}` queries.
As Procedures are introduced in PG11, the code contains many PG version checks. I tried my best to make it easy to clean up once we drop PG10 support.
Here are some caveats:
- I assumed that the parse tree is a valid one. There are some queries that are not allowed, but still are parsed successfully by postgres planner. Such queries will result in errors in execution time. (e.g. `ALTER PROCEDURE p STRICT` -> `STRICT` action is valid for functions but not procedures. Postgres decides to parse them nevertheless.)
DESCRIPTION: Distribute Types to worker nodes
When to propagate
==============
There are two logical moments that types could be distributed to the worker nodes
- When they get used ( just in time distribution )
- When they get created ( proactive distribution )
The just in time distribution follows the model used by how schema's get created right before we are going to create a table in that schema, for types this would be when the table uses a type as its column.
The proactive distribution is suitable for situations where it is benificial to have the type on the worker nodes directly. They can later on be used in queries where an intermediate result gets created with a cast to this type.
Just in time creation is always the last resort, you cannot create a distributed table before the type gets created. A good example use case is; you have an existing postgres server that needs to scale out. By adding the citus extension, add some nodes to the cluster, and distribute the table. The type got created before citus existed. There was no moment where citus could have propagated the creation of a type.
Proactive is almost always a good option. Types are not resource intensive objects, there is no performance overhead of having 100's of types. If you want to use them in a query to represent an intermediate result (which happens in our test suite) they just work.
There is however a moment when proactive type distribution is not beneficial; in transactions where the type is used in a distributed table.
Lets assume the following transaction:
```sql
BEGIN;
CREATE TYPE tt1 AS (a int, b int);
CREATE TABLE t1 AS (a int PRIMARY KEY, b tt1);
SELECT create_distributed_table('t1', 'a');
\copy t1 FROM bigdata.csv
```
Types are node scoped objects; meaning the type exists once per worker. Shards however have best performance when they are created over their own connection. For the type to be visible on all connections it needs to be created and committed before we try to create the shards. Here the just in time situation is most beneficial and follows how we create schema's on the workers. Outside of a transaction block we will just use 1 connection to propagate the creation.
How propagation works
=================
Just in time
-----------
Just in time propagation hooks into the infrastructure introduced in #2882. It adds types as a supported object in `SupportedDependencyByCitus`. This will make sure that any object being distributed by citus that depends on types will now cascade into types. When types are depending them self on other objects they will get created first.
Creation later works by getting the ddl commands to create the object by its `ObjectAddress` in `GetDependencyCreateDDLCommands` which will dispatch types to `CreateTypeDDLCommandsIdempotent`.
For the correct walking of the graph we follow array types, when later asked for the ddl commands for array types we return `NIL` (empty list) which makes that the object will not be recorded as distributed, (its an internal type, dependant on the user type).
Proactive distribution
---------------------
When the user creates a type (composite or enum) we will have a hook running in `multi_ProcessUtility` after the command has been applied locally. Running after running locally makes that we already have an `ObjectAddress` for the type. This is required to mark the type as being distributed.
Keeping the type up to date
====================
For types that are recorded in `pg_dist_object` (eg. `IsObjectDistributed` returns true for the `ObjectAddress`) we will intercept the utility commands that alter the type.
- `AlterTableStmt` with `relkind` set to `OBJECT_TYPE` encapsulate changes to the fields of a composite type.
- `DropStmt` with removeType set to `OBJECT_TYPE` encapsulate `DROP TYPE`.
- `AlterEnumStmt` encapsulates changes to enum values.
Enum types can not be changed transactionally. When the execution on a worker fails a warning will be shown to the user the propagation was incomplete due to worker communication failure. An idempotent command is shown for the user to re-execute when the worker communication is fixed.
Keeping types up to date is done via the executor. Before the statement is executed locally we create a plan on how to apply it on the workers. This plan is executed after we have applied the statement locally.
All changes to types need to be done in the same transaction for types that have already been distributed and will fail with an error if parallel queries have already been executed in the same transaction. Much like foreign keys to reference tables.
Naisila Puka
Nils Dijk
Marco Slot
SaitTalhaNisanci
Ahmet Gedemenli
Halil Ozan Akgul
Onur Tirtir
nukoyluoglu
Hanefi Önaldı
Jelte Fennema
Philip Dubé
MoYi
Hanefi Onaldi
Onder Kalaci
Hanefi Onaldi