Incremental Backup and Restore with SQL

Incremental backup and restore operations can be performed from any SQL client by executing the eXtremeSQL extensions BACKUP , VERIFY and RESTORE. (Also note that file backup can be performed for persistent databases by calling SQL function file_backup().)

BACKUP

The BACKUP statement must specify the backup type as one of the following:

• FULL backup (snapshot), which creates a backup record for the entire database,
• INCREMENTAL (partial), which records only the database modifications since the previous backup, or
• AUTO which creates a FULL or INCREMENTAL backup record depending on the content of the backup file: If there is no snapshot in the file yet the backup process will create one; otherwise a partial backup record is created.

The statement and can also specify an optional label. For example:

 
     
    BACKUP 'SimpleDb_backup' FULL 'Initial full'
     
    or
            
     
    BACKUP 'SimpleDb_backup' INCREMENTAL '06/15/2016'
     
    or
            
     
    BACKUP 'SimpleDb_backup' AUTO 'Autobkp'
     

Note that a FULL backup must be done at least once before an INCREMENTAL backup can be done successfully.

RESTORE a backup

To restore the database the RESTORE statement specifies the backup file and an optional label (to restore the database contents up to that label only). For example:

 
    RESTORE 'SimpleDb_backup' TO '06/15/2016'
 

List the backup contents

The SELECT statement can be used to list the contents of a backup file. For example:

     
    SELECT * FROM BACKUP 'SimpleDb_backup'
     

VERIFY a backup

The VERIFY statement can be used to verify that a backup file will produce a successfully restored database. For example:

 
    VERIFY 'SimpleDb_backup' LABEL '06/15/2016'