Backup & Restore
Data in databases is backed up remotely to protect against disaster. In case of a disaster event, the backups can be restored to a database on request.
Exasol SaaS uses periodic database snapshots of the underlying data blocks to allow a very fast recovery time in case of errors. Additionally, backups of these database snapshots are created to allow for disaster recovery.
Backups are the primary disaster recovery mechanism because a copy of the database is stored in a separate S3 bucket. If something happens to the underlying storage layer of the database, Exasol can create a new database built on the backup to restore availability.
During a backup, the database performs an incremental sync between the data in the local S3 bucket and the data in the remote S3 bucket. During this sync, all data blocks which were modified since the last backup are copied to a separate S3 bucket. Since this sync is incremental, we minimize the duration of the sync and the network utilization by only transferring data which was recently modified. Therefore, the duration of the backup is highly dependent on the amount of data that was modified.
Information concerning backups is not visible in any system table.
The database must be online for a backup to take place. If the database is shut down during the backup, the operation is aborted. As a result, the next backup which occurs may take longer because more data needs to be synchronized. This may result in a database running without a valid backup for disaster recovery.
While the database is running, backups are created and synced incrementally throughout the day. These daily backups have an expiry time of 7 days.
Modifying the backup schedule or running a manual backup is not supported.
On request, Exasol can perform a restore of a backup. Restoring a backup requires a downtime. The duration of the downtime depends on the size of the backup to be restored.
To execute a restore, send a support request. To send a support request, click Help and then click Support.