add_columnstore_policy.md

api_name	excerpt	topics	keywords	tags	products	api
add_columnstore_policy()	Set a policy to automatically move chunks in a hypertable to the columnstore when they reach a given age.	hypercore columnstore jobs	columnstore hypercore policies	scheduled jobs background jobs automation framework	cloud self_hosted	license type community procedure

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add_columnstore_policy()

Create a job that automatically moves chunks in a hypertable to the columnstore after a specific time interval.

You enable the columnstore a hypertable or continuous aggregate before you create a columnstore policy. You do this by calling ALTER TABLE for hypertables and ALTER MATERIALIZED VIEW for continuous aggregates.

To view the policies that you set or the policies that already exist, see informational views, to remove a policy, see remove_columnstore_policy.

Samples

To create a columnstore job:

1. Enable columnstore

   • Use ALTER TABLE for a hypertable

     ALTER TABLE crypto_ticks SET (
        timescaledb.enable_columnstore = true, 
        timescaledb.segmentby = 'symbol');

   • Use ALTER MATERIALIZED VIEW for a continuous aggregate

     ALTER MATERIALIZED VIEW assets_candlestick_daily set (
        timescaledb.enable_columnstore = true, 
        timescaledb.segmentby = 'symbol' );

2. Add a policy to move chunks to the columnstore at a specific time interval

   For example:

   • 60 days after the data was added to the table:

     CALL add_columnstore_policy('crypto_ticks', after => INTERVAL '60d');

   • 3 months prior to the moment you run the query:

     CALL add_columnstore_policy('crypto_ticks', created_before => INTERVAL '3 months');

   • With an integer-based time column:

     CALL add_columnstore_policy('table_with_bigint_time', BIGINT '600000');

   • Older than eight weeks:

     CALL add_columnstore_policy('cpu_weekly', INTERVAL '8 weeks');

   • Older than eight weeks and using the Hypercore table access method:

     CALL add_columnstore_policy(
       'cpu_weekly', 
       INTERVAL '8 weeks', 
       hypercore_use_access_method => true);

3. View the policies that you set or the policies that already exist

   SELECT * FROM timescaledb_information.jobs
   WHERE proc_name='policy_compression';

   See timescaledb_information.jobs.

Arguments

Calls to add_columnstore_policy require either after or created_before, but cannot have both.

Name	Type	Default	Required	Description
hypertable	REGCLASS	-	✔	Name of the hypertable or continuous aggregate to run this job on.
after	INTERVAL or INTEGER	-	✖	Add chunks containing data older than now - {after}::interval to the columnstore. Use an object type that matchs the time column type in hypertable: TIMESTAMP, TIMESTAMPTZ, or DATE: use an INTERVAL type. Integer-based timestamps : set an integer type using the integer_now_func. after is mutually exclusive with created_before.
created_before	INTERVAL	NULL	✖	Add chunks with a creation time of now() - created_before to the columnstore. created_before is Not supported for continuous aggregates. Mutually exclusive with after.
schedule_interval	INTERVAL	12 hours when chunk_time_interval >= 1 day for hypertable. Otherwise chunk_time_interval / 2.	✖	Set the interval between the finish time of the last execution of this policy and the next start.
initial_start	TIMESTAMPTZ	The interval from the finish time of the last execution to the next_start.	✖	Set the time this job is first run. This is also the time that next_start is calculated from.
timezone	TEXT	UTC. However, daylight savings time(DST) changes may shift this alignment.	✖	Set to a valid time zone to mitigate DST shifting. If initial_start is set, subsequent executions of this policy are aligned on initial_start.
if_not_exists	BOOLEAN	false	✖	Set to true so this job fails with a warning rather than an error if a columnstore policy already exists on hypertable
hypercore_use_access_method	BOOLEAN	NULL	✖	Set to true to use hypercore table access metod. If set to NULL it will use the value from timescaledb.default_hypercore_use_access_method.