With the introduction of #4385 we inadvertently started allowing and
pushing down certain lateral subqueries that were unsafe to push down.
To be precise the type of LATERAL subqueries that is unsafe to push down
has all of the following properties:
1. The lateral subquery contains some non recurring tuples
2. The lateral subquery references a recurring tuple from
outside of the subquery (recurringRelids)
3. The lateral subquery requires a merge step (e.g. a LIMIT)
4. The reference to the recurring tuple should be something else than an
equality check on the distribution column, e.g. equality on a non
distribution column.
Property number four is considered both hard to detect and probably not
used very often. Thus this PR ignores property number four and causes
query planning to error out if the first three properties hold.
Fixes#5327
TEXT SEARCH DICTIONARY objects depend on TEXT SEARCH TEMPLATE objects.
Since we do not yet support distributed TS TEMPLATE objects, we skip
dependency checks for text search templates, similar to what we do for
roles.
The user is expected to manually create the TEXT SEARCH TEMPLATE objects
before a) adding new nodes, b) creating TEXT SEARCH DICTIONARY objects.
If a worker node is being added, a command is sent to get the server_id of the worker from the pg_dist_node_metadata table. If the worker's id is the same as the node executing the code, we will know the node is trying to add itself. If the node tries to add itself without specifying `groupid:=0` the operation will result in an error.
Using CASCADE in a DELETE can inadvertently delete things we don't
intend to. It's safer to fail hard and make the user delete depending
things manually.
1) Remove useless columns
2) Show backends that are blocked on a DDL even before
gpid is assigned
3) One minor bugfix, where we clear distributedCommandOriginator
properly.
DESCRIPTION: Move pg_dist_object to pg_catalog
Historically `pg_dist_object` had been created in the `citus` schema as an experiment to understand if we could move our catalog tables to a branded schema. We quickly realised that this interfered with the UX on our managed services and other environments, where users connected via a user with the name of `citus`.
By default postgres put the username on the search_path. To be able to read the catalog in the `citus` schema we would need to grant access permissions to the schema. This caused newly created objects like tables etc, to default to this schema for creation. This failed due to the write permissions to that schema.
With this change we move the `pg_dist_object` catalog table to the `pg_catalog` schema, where our other schema's are also located. This makes the catalog table visible and readable by any user, like our other catalog tables, for debugging purposes.
Note: due to the change of schema, we had to disable 1 test that was running into a discrepancy between the schema and binary. Secondly, we needed to make the lookup functions for the `pg_dist_object` relation and their indexes less strict on the fallback of the naming due to an other test that, due to an unfortunate cache invalidation, needed to lookup the relation again. This makes that we won't default to _only_ resolving from `pg_catalog` outside of upgrades.
* Notice when create_distributed_function called without params
* Move variable comments to top
* Add valid check for cache entry
* add objtype to notice msg
* update test outputs
* Add more tests
* Address feedback
And also citus_calculate_gpid(nodeId,pid). These UDFs are just
wrappers for the existing functions. Useful for testing and simple
manipulation of citus_stat_activity.
It seems like our approach is way too restrictive and some places
are wrong. Now, we follow very similar approach to pg_stat_activity.
Some of the changes are pre-requsite for implementing citus_dist_stat_activity
via citus_stat_activity.
Clusters created pre-Citus 11 mostly didn't have metadata sync enabled.
For those clusters, we add a utility UDF which fixes some minor issues
and sync the necessary objects to the workers.
* [Columnar] Build columnar.so and let citus depends on it
Co-authored-by: Yanwen Jin <yanwjin@microsoft.com>
Co-authored-by: Ying Xu <32597660+yxu2162@users.noreply.github.com>
Co-authored-by: jeff-davis <Jeffrey.Davis@microsoft.com>
DESCRIPTION: Add GUC to control ddl creation behaviour in transactions
Historically we would _not_ propagate objects when we are in a transaction block. Creation of distributed tables would not always work in sequential mode, hence objects created in the same transaction as distributing a table that would use the just created object wouldn't work. The benefit was that the user could still benefit from parallelism.
Now that the creation of distributed tables is supported in sequential mode it would make sense for users to force transactional consistency of ddl commands for distributed tables. A transaction could switch more aggressively to sequential mode when creating new objects in a transaction.
We don't change the default behaviour just yet.
Also, many objects would not even propagate their creation when the transaction was already set to sequential, leaving the probability of a self deadlock. The new policy checks solve this discrepancy between objects as well.
The issue in question is caused when rebalance / replication call `FullShardPlacementList` which returns all shard placements (including those in disabled nodes with `citus_disable_node`). Eventually, `FindFillStateForPlacement` looks for the state across active workers and fails to find a state for the placements which are in the disabled workers causing a seg fault shortly after.
Approach:
* `ActivePlacementHash` was not using the status of the shard placement's node to determine if the node it is active. Initially, I just fixed that.
* Additionally, I refactored the code which handles active shards in replication / rebalance to:
* use a single function to determine if a shard placement is active.
* do the shard active shard filtering before calling `RebalancePlacementUpdates` and `ReplicationPlacementUpdates`, so test methods like `shard_placement_rebalance_array` and `shard_placement_replication_array` which have different shard placement active requirements can do their own filtering while using the same rebalance / replicate logic that `rebalance_table_shards` and `replicate_table_shards` use.
Fix#5664
CitusInitiatedBackend was a pre-mature implemenation of the whole
GlobalPID infrastructure. We used it to track whether any individual
query is triggered by Citus or not.
As of now, after GlobalPID is already in place, we don't need
CitusInitiatedBackend, in fact it could even be wrong.
Marco Slot
Ahmet Gedemenli
Jelte Fennema
Halil Ozan Akgül
Hanefi Onaldi
Marco Slot
Gledis Zeneli
Burak Velioglu
Onder Kalaci
Nils Dijk
ywj