November 3, 2003 at 2:48 pm
I know in previous versions of SQL, a database backup was a snapshot in time from when the backup started. For example, if a backup started at 7:00 PM, and ran for 2 hours, when restored, the data would be as of 7:00 PM, not 9:00 PM.
Has this behavior changed? In SQL 2000, when I restore a backup taken at 1:00 AM that runs for 2 hours, the data appears to be from 3:00 AM, not 1:00 AM.
Thanks,
Luke
November 3, 2003 at 3:18 pm
This changed between versions 6 and 7. The method was changed to a "fuzzy" backup where there is no "snapshot" synchonization but instead extents are backed up serially and then the recovery process brings the data to the state at the end of the backup by using the tran log.
--Jonathan
--Jonathan
November 3, 2003 at 3:21 pm
Thanks Jonathan.
Does that mean that the backup, when restored (with recovery), is a snapshot in time at the instant the backup job finished?
November 3, 2003 at 3:52 pm
quote:
Thanks Jonathan.Does that mean that the backup, when restored (with recovery), is a snapshot in time at the instant the backup job finished?
Yes. From BOL:
quote:
The database modifications recorded in the log are rolled forward to the end of the log, and then any incomplete transactions are rolled back. This returns the database to a consistent, recovered state that corresponds to the state the database was in at the time the BACKUP statement completed.
--Jonathan
--Jonathan
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