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

2. SELECT move_chunk(

4. chunk => '_timescaledb_internal._hyper_1_4_chunk',

6. destination_tablespace => 'tablespace_2',

8. index_destination_tablespace => 'tablespace_3',

10. reorder_index => 'conditions_device_id_time_idx',

12. verbose => TRUE

14. );