DuckLake in normal operation never removes any data, even when tables are dropped or data is deleted. Due to time travel, the removed data is still accessible.
Data can only be physically removed from DuckLake by expiring snapshots that refer to the old data.
This can be done using the ducklake_expire_snapshots function.
Warning Snapshot expiration is supported only at the catalog level. As a result,
expire_older_thancan only be configured at the global scope. Attempting to set this option at any other scope is not supported and will result in an error.
Usage
The below command expires a snapshot with a specific snapshot id.
CALL ducklake_expire_snapshots('my_ducklake', versions => [2]);
The below command expires snapshots older than a week.
CALL ducklake_expire_snapshots('my_ducklake', older_than => now() - INTERVAL '1 week');
The below command performs a dry run, which only lists the snapshots that will be deleted, instead of actually deleting them.
CALL ducklake_expire_snapshots('my_ducklake', dry_run => true, older_than => now() - INTERVAL '1 week');
It is also possible to set a DuckLake option to expire snapshots that applies to the whole catalog.
CALL my_ducklake.set_option('expire_older_than', '1 month');
Cleaning Up Files
Note that expiring snapshots does not immediately delete files that are no longer referenced. See the cleanup old files section on how to trigger a cleanup of these files.