The database has to be shut down prior to any restore. The result of a restore is that the database will be in the state it was when the backup restored from was started. Any changes applied to the database after that backup are lost. Exasol does not support Point-In-Time recovery; a database state from the past can only be reached according to the backup start times done in the past, assumed those backups are available.
The data distribution inside of an Exasol database depends on the number of cluster nodes. Therefore, a backup can only be restored to a cluster with the same number of nodes as the cluster where the backup was taken before.
You can restore a database from a database backup in the following ways:
This is the fastest way to restore a database, however the database cannot be used during the restore process and it also prevents connections to the database until the restore is finished. Blocking restore is supported from a local archive volume and from a remote archive volume.
Allows connections to the database while the restore is ongoing in the background. If sessions request blocks that have not yet been restored, these blocks are restored with priority. Non-blocking restore is supported from a local archive volume.
Restore is limited to blocks requested by connected sessions. The database is opened in a special state: Changes are allowed but these changes are not persisted on Data Volumes. Virtual access restore is supported from a local archive volume.
See Restore Database Instance from Backup to know how to restore a database from a backup.