attach_data_node.md

api_name	attach_data_node()
excerpt	Attach a data node to a distributed hypertable
topics	distributed hypertables multi-node
keywords	multi-node distributed hypertables
tags	distributed hypertables data nodes attach
api	license type community function
seo	robots noindex

import MultiNodeDeprecation from "versionContent/_partials/_multi-node-deprecation.mdx";

attach_data_node() Community

Attach a data node to a hypertable. The data node should have been previously created using add_data_node.

When a distributed hypertable is created, by default it uses all available data nodes for the hypertable, but if a data node is added after a hypertable is created, the data node is not automatically used by existing distributed hypertables.

If you want a hypertable to use a data node that was created later, you must attach the data node to the hypertable using this function.

Required arguments

Name	Description
node_name	Name of data node to attach
hypertable	Name of distributed hypertable to attach node to

Optional arguments

Name	Description
if_not_attached	Prevents error if the data node is already attached to the hypertable. A notice is printed that the data node is attached. Defaults to FALSE.
repartition	Change the partitioning configuration so that all the attached data nodes are used. Defaults to TRUE.

Returns

Column	Description
hypertable_id	Hypertable id of the modified hypertable
node_hypertable_id	Hypertable id on the remote data node
node_name	Name of the attached data node

Sample usage

Attach a data node dn3 to a distributed hypertable conditions previously created with create_distributed_hypertable.

SELECT * FROM attach_data_node('dn3','conditions');

hypertable_id | node_hypertable_id |  node_name
--------------+--------------------+-------------
            5 |                  3 | dn3

(1 row)

You must add a data node to your distributed database first with add_data_node first before attaching it.