disable_chunk_skipping()

Early access 2.16.0

Disable range tracking for a specific column in a hypertable in the columnstore.

Samples

In this sample, you convert the conditions table to a hypertable with partitioning on the time column. You then specify and enable additional columns to track ranges for. You then disable range tracking:

SELECT create_hypertable('conditions', 'time');
SELECT enable_chunk_skipping('conditions', 'device_id');
SELECT disable_chunk_skipping('conditions', 'device_id');

Note

Best practice is to enable range tracking on columns which are correlated to the partitioning column. In other words, enable tracking on secondary columns that are referenced in the WHERE clauses in your queries. Use this API to disable range tracking on columns when the query patterns don’t use this secondary column anymore.

Arguments

The syntax is:

SELECT disable_chunk_skipping(
    hypertable = '<hypertable_name>',
    column_name = '<column_name>',
    if_not_exists = true | false
);

Name	Type	Default	Required	Description
hypertable	REGCLASS	-	✔	Hypertable that the column belongs to
column_name	NAME	-	✔	Column to disable tracking range statistics for
if_not_exists	BOOLEAN	FALSE	✖	Set to true so that a notice is sent when ranges are not being tracked for a column. By default, an error is thrown

Returns

Column	Type	Description
hypertable_id	INTEGER	ID of the hypertable in TimescaleDB.
column_name	NAME	Name of the column range tracking is disabled for
disabled	BOOLEAN	Returns true when tracking is disabled. false when if_not_exists is true and the entry was not removed

Note

To disable_chunk_skipping(), you must have first called enable_chunk_skipping and enabled range tracking on a column in the hypertable.