Expiring snapshots

You can expire snapshots of an Iceberg table using an ALTER TABLE query from Hive or Impala. You should periodically expire snapshots to delete data files that are no longer needed, and reduce the size of table metadata.

Each write to an Iceberg table creates a new snapshot, or version, of a table. Snapshots can be used for time-travel queries, or the table can be rolled back to any valid snapshot. Snapshots accumulate until they are expired by the expire_snapshots operation.

Enter a query to expire snapshots having the following timestamp: '2021-12-09 05:39:18.689000000'

ALTER TABLE test_table EXECUTE expire_snapshots('2021-12-09 05:39:18.689000000');