Tradionally our planner works in the following order:
router - > pushdown -> repartition -> pull to coordinator
However, for INSERT .. SELECT commands, we did not support "router".
In practice, that is not a big issue, because pushdown planning can
handle router case as well.
However, with PG 16, certain outer joins are converted to JOIN without
any conditions (e.g., JOIN .. ON (true)) and the filters are pushed down
to the tables.
When the filters are pushed down to the tables, router planner can
detect. However, pushdown planner relies on JOIN conditions.
An example query:
```
INSERT INTO agg_events (user_id)
SELECT raw_events_first.user_id
FROM raw_events_first LEFT JOIN raw_events_second
ON raw_events_first.user_id = raw_events_second.user_id
WHERE raw_events_first.user_id = 10;
```
As a side effect of this change, now we can also relax certain
limitation that "pushdown" planner emposes, but not "router". So, with
this PR, we also allow those.
Closes https://github.com/citusdata/citus/pull/6772
DESCRIPTION: Prevents unnecessarily pulling the data into coordinator
for some INSERT .. SELECT queries that target a single-shard group
Previously, we only checked whether the relations are colocated, but we
ignore the shard indexes. That causes certain queries still to be
accidentally router. We should enforce colocation checks for both shard
index and table colocation id to make the check restrictive enough.
For example, the following query should not be router, and after this
patch, it won't:
```SQL
SELECT
user_id
FROM
((SELECT user_id FROM raw_events_first WHERE user_id = 15) EXCEPT
(SELECT user_id FROM raw_events_second where user_id = 17)) as foo;
```
DESCRIPTION: Enforce shard level colocation with
citus.enable_non_colocated_router_query_pushdown
Changes test files in multi and multi-1 schedules such that they
accomodate coordinator in metadata.
Changes fall into the following buckets:
1. When coordinator is in metadata, reference table shards are present
in coordinator too.
This changes test outputs checking the table size, shard numbers etc.
for reference tables.
2. When coordinator is in metadata, postgres tables are converted to
citus local tables whenever a foreign key relationship to them is
created. This changes some test cases which tests it should not be
possible to create foreign keys to postgres tables.
3. Remove lines that add/remove coordinator for testing purposes.
Previously INSERT .. SELECT planner were pushing down some queries that should not be pushed down due to wrong colocation checks. It was checking whether one of the table in SELECT part and target table are colocated. But now, we check colocation for all tables in SELECT part and the target table.
Another problem with INSERT .. SELECT planner was that some queries, which is valid to be pushed down, were not pushed down due to unnecessary checks which are currently supported. e.g. UNION check. As solution, we reused the pushdown planner checks for INSERT .. SELECT planner.
DESCRIPTION: Fixes a bug that causes incorrectly pushing down some
INSERT .. SELECT queries that we shouldn't
DESCRIPTION: Prevents unnecessarily pulling the data into coordinator
for some INSERT .. SELECT queries
DESCRIPTION: Drops support for pushing down INSERT .. SELECT with append
table as target
Fixes#6749.
Fixes#1428.
Fixes#6920.
---------
Co-authored-by: aykutbozkurt <aykut.bozkurt1995@gmail.com>
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.
Fixes#6779.
DESCRIPTION: Disables citus.enable_non_colocated_router_query_pushdown
GUC by default to ensure generating a consistent distributed plan for
the queries that reference non-colocated distributed tables
We already have tests for the cases where this GUC is disabled,
so I'm not adding any more tests in this PR.
Also make multi_insert_select_window idempotent.
Related to: #6793
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