DROP BACKUP CHAIN

Drop a backup chain. Optionally, also drop its backup snapshots.

DROP BACKUP CHAIN 'chain_name' [ CASCADE ]

Use the CASCADE option to drop the snapshots that belong to the specified backup chain. Typically, you should run the command with this option.

Run this command when you plan on no longer taking backups from a specific database. When you drop a backup chain, the system reclaims space previously taken up by delete information that was pending the next backup. When a backup chain has been dropped, it can no longer be used for incremental or cumulative backups.

Run the command from the database that owns the chain. Chains are database-specific.

Although the ybbackupctl client tool provides a command to delete physical backups, this command does not connect to the database and does not drop the referenced backup chain.

For example, the August2020 backup chain for database premdb has the following snapshots:
premdb=# select * from sys.backup_snapshot;
 database_id | backup_txid |  backup_txsnap   |                 snapshot_name                  |         creation_time         
-------------+-------------+------------------+------------------------------------------------+-------------------------------
       16395 |      175440 | 0:175440:175440: | Aug21Full                                      | 2020-08-21 13:20:37.795147-07
       16395 |      177767 | 0:177767:177767: | Aug21Incr                                      | 2020-08-21 13:22:09.254674-07
       16395 |      177989 | 0:177989:177989: | Aug21IncrNew                                   | 2020-08-21 13:24:38.32832-07
       16395 |      175439 | 0:3:3:           | ybd_cf861c56-0cf7-19a8-f459-3382036212c8_epoch | 2020-08-21 13:20:37.781983-07
(4 rows)
The following command drops the chain and all the associated snapshots:
premdb=# drop backup chain 'August2020' cascade;
DROP BACKUP CHAIN
premdb=# select * from sys.backup_chain;
 database_id | chain_name | policy | oldest_backup_point_id | oldest_rollback_point_id | inprogress_backup_point_id | creation_time 
-------------+------------+--------+------------------------+--------------------------+----------------------------+---------------
(0 rows)
premdb=# select * from sys.backup_snapshot;
 database_id | backup_txid | backup_txsnap | snapshot_name | creation_time 
-------------+-------------+---------------+---------------+---------------
(0 rows)