Create a policy to reorder chunks on a given hypertable index in the background. You can have only one reorder policy on each hypertable. Only chunks that are the third from the most recent are reordered to avoid reordering chunks that are still being inserted into. For more information about reordering chunks, see the reorder_chunk section.

Note

When a chunk has been reordered by the background worker it is not reordered again. If you insert significant amounts of data in to older chunks that have already been reordered, you might need to manually re-run the reorderchunk function on older chunks. Alternatively, you can drop and re-create the policy, which can work better if you have changed a lot of older chunks.

NameTypeDescription
hypertableREGCLASSHypertable to create the policy for
index_nameTEXTExisting index by which to order rows on disk
initial_startTIMESTAMPTZTime the policy is first run. Defaults to NULL. If omitted, then the schedule interval is the interval between the finish time of the last execution and the next start. If provided, it serves as the origin with respect to which the next_start is calculated
timezoneTEXTA valid time zone. If initial_start is also specified, subsequent executions of the reorder policy are aligned on its initial start. However, daylight savings time (DST) changes might shift this alignment. Set to a valid time zone if this is an issue you want to mitigate. If omitted, UTC bucketing is performed. Defaults to NULL.
NameTypeDescription
if_not_existsBOOLEANSet to true to avoid an error if the reorder_policy already exists. A notice is issued instead. Defaults to false.
ColumnTypeDescription
job_idINTEGERTimescaleDB background job ID created to implement this policy
SELECT add_reorder_policy('conditions', 'conditions_device_id_time_idx');

Creates a policy to reorder chunks by the existing (device_id, time) index. This applies to chunks that are complete, and are no longer being written to. For more information about reordering chunks, see the reorder_chunk section.

Keywords

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