Creating a tiering policy

To automate the archival of data not actively accessed, create a tiering policy that automatically moves data to the object storage tier. Any chunks that only contain data older than the move_after threshold are moved. This works similarly to a data retention policy, but chunks are moved rather than deleted.

The tiering policy schedules a job that runs periodically to migrate eligible chunks. The migration is asynchronous. The chunks are tiered once they appear in the timescaledb_osm.tiered_chunks view. Tiering does not influence your ability to query the chunks.

To add a tiering policy, use the add_tiering_policy function:

SELECT add_tiering_policy(hypertable REGCLASS, move_after INTERVAL);

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In this example, you use a hypertable called example, and tier chunks older than three days.

Adding a tiering policy

1. At the psql prompt, select the hypertable and duration:

SELECT add_tiering_policy('example', INTERVAL '3 days');

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To remove an existing tiering policy, use the remove_tiering_policy function:

SELECT remove_tiering_policy(hypertable REGCLASS, if_exists BOOL = false);

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Removing a tiering policy

1. At the psql prompt, select the hypertable to remove the policy from:

SELECT remove_tiering_policy('example');

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If you remove a tiering policy, the removal automatically prevents scheduled chunks from being tiered in the future. Any chunks that were already tiered won't be untiered automatically. You can use the untier_chunk procedure to untier chunks to local storage that have already been tiered.

To see which chunks are tiered into the object storage tier, use the tiered_chunks informational view:

SELECT * FROM timescaledb_osm.tiered_chunks;

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If you need to untier your data, see the manually untier data section.