move_chunk()
TimescaleDB allows you to move data and indexes to different tablespaces. This allows you to move data to more cost-effective storage as it ages.
The move_chunk
function acts like a combination of the PostgreSQL CLUSTER command and PostgreSQL ALTER TABLE…SET TABLESPACE commands. Unlike these PostgreSQL commands, however, the move_chunk
function uses lower lock levels so that the chunk and hypertable are able to be read for most of the process. This comes at a cost of slightly higher disk usage during the operation. For a more detailed discussion of this capability, see the documentation on managing storage with tablespaces.
note
You must be logged in as a super user, such as the postgres
user, to use the move_chunk()
call.
Required arguments
Name | Type | Description |
---|---|---|
chunk | REGCLASS | Name of chunk to be moved |
destination_tablespace | NAME | Target tablespace for chunk being moved |
index_destination_tablespace | NAME | Target tablespace for index associated with the chunk you are moving |
Optional arguments
Name | Type | Description |
---|---|---|
reorder_index | REGCLASS | The name of the index (on either the hypertable or chunk) to order by |
verbose | BOOLEAN | Setting to true displays messages about the progress of the move_chunk command. Defaults to false. |
Sample usage
SELECT move_chunk(
chunk => '_timescaledb_internal._hyper_1_4_chunk',
destination_tablespace => 'tablespace_2',
index_destination_tablespace => 'tablespace_3',
reorder_index => 'conditions_device_id_time_idx',
verbose => TRUE
);