disable_chunk_skipping() - Tiger Data

Early access Since 2.16.0 Disable range tracking for a specific column in a in the .

Samples

In this sample, you convert the conditions table to a 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');

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 in .
`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

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