Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Remove references to master_get_table_metadata #1124

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Remove references to master_get_table_metadata #1124

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
58 changes: 8 additions & 50 deletions develop/api_udf.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -411,11 +411,11 @@ update_distributed_table_colocation
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

The update_distributed_table_colocation() function is used to update colocation
of a distributed table. This function can also be used to break colocation of a
of a distributed table. This function can also be used to break colocation of a
distributed table. Citus will implicitly colocate two tables if the distribution
column is the same type, this can be useful if the tables are related and will
do some joins. If table A and B are colocated, and table A gets rebalanced, table B
will also be rebalanced. If table B does not have a replica identity, the rebalance will
column is the same type, this can be useful if the tables are related and will
do some joins. If table A and B are colocated, and table A gets rebalanced, table B
will also be rebalanced. If table B does not have a replica identity, the rebalance will
fail. Therefore, this function can be useful breaking the implicit colocation in that case.

Note that this function does not move any data around physically.
Expand Down Expand Up @@ -450,7 +450,7 @@ Assume that ``table A`` and ``table B`` are colocated( possibily implicitly), if

SELECT update_distributed_table_colocation('A', colocate_with => 'none');

Now, assume that ``table A``, ``table B``, ``table C`` and ``table D`` are colocated and you want to colocate ``table A``
Now, assume that ``table A``, ``table B``, ``table C`` and ``table D`` are colocated and you want to colocate ``table A``
and ``table B`` together, and ``table C`` and ``table D`` together:

.. code-block:: postgresql
Expand Down Expand Up @@ -998,9 +998,9 @@ Example
.. code-block:: postgresql

select citus_remove_node('new-node', 12345);
citus_remove_node
citus_remove_node
--------------------

(1 row)

citus_get_active_worker_nodes
Expand Down Expand Up @@ -1029,7 +1029,7 @@ Example
.. code-block:: postgresql

SELECT * from citus_get_active_worker_nodes();
node_name | node_port
node_name | node_port
-----------+-----------
localhost | 9700
localhost | 9702
Expand Down Expand Up @@ -1174,48 +1174,6 @@ Example
-- then add a worker
SELECT * FROM citus_add_node('worker1.example.com', 5432);

master_get_table_metadata
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

The master_get_table_metadata() function can be used to return distribution related metadata for a distributed table. This metadata includes the relation id, storage type, distribution method, distribution column, replication count (deprecated), maximum shard size and the shard placement policy for that table. Behind the covers, this function queries Citus metadata tables to get the required information and concatenates it into a tuple before returning it to the user.

Arguments
***********************

**table_name:** Name of the distributed table for which you want to fetch metadata.

Return Value
*********************************

A tuple containing the following information:

**logical_relid:** Oid of the distributed table. This values references the relfilenode column in the pg_class system catalog table.

**part_storage_type:** Type of storage used for the table. May be 't' (standard table), 'f' (foreign table) or 'c' (columnar table).

**part_method:** Distribution method used for the table. Must be 'h' (hash).

**part_key:** Distribution column for the table.

**part_replica_count:** (Deprecated) Current shard replication count.

**part_max_size:** Current maximum shard size in bytes.

**part_placement_policy:** Shard placement policy used for placing the table’s shards. May be 1 (local-node-first) or 2 (round-robin).

Example
*************************

The example below fetches and displays the table metadata for the github_events table.

.. code-block:: postgresql

SELECT * from master_get_table_metadata('github_events');
logical_relid | part_storage_type | part_method | part_key | part_replica_count | part_max_size | part_placement_policy
---------------+-------------------+-------------+----------+--------------------+---------------+-----------------------
24180 | t | h | repo_id | 1 | 1073741824 | 2
(1 row)

.. _get_shard_id:

get_shard_id_for_distribution_column
Expand Down