Backup history

The firebird database keeps a history of all nbackup activity in the system table RDB$BACKUP_HISTORY. This information is used by nbackup itself for internal housekeeping, but can also be used to find out when the last backup was done, on which level and what the filename is.

For example, to see the last 5 backups you can use:

SELECT RDB$BACKUP_ID, RDB$TIMESTAMP, RDB$BACKUP_LEVEL, RDB$GUID, 
    RDB$SCN, RDB$FILE_NAME
FROM RDB$BACKUP_HISTORY
ORDER BY RDB$TIMESTAMP DESC
ROWS 5

The columns of RDB$BACKUP_HISTORY are:

Column	Description
RDB$BACKUP_ID	Primary key
RDB$TIMESTAMP	Time and date of backup
RDB$BACKUP_LEVEL	Backup level
RDB$GUID	GUID of the backup (used to check dependencies between files)
RDB$SCN	Highest page marker in the backup
RDB$FILE_NAME	Filename of the backup

For an explanation of the field RDB$SCN see the section Technical background information.

The contents of the table RDB$BACKUP_HISTORY are not backed up and restored by gbak; see the section Technical background information for details.