January 22, 2013 at 11:53 pm
First let me apologize if this is not the correct palace for this topic but it is strongly connected.
when we perform a full database backup the engine marks the place in the database from where all new transaction should be kept in the next transaction log packup.
what is not cleared to me is where is the transaction that started before the full backup started and ends
1. during the full backup ?
2. after the full backup completed ?
3. after a few transaction logs where also backed up after the full backup completed
Backed up in which backup file will I find it ?
for the connivance of the discussion lets say that a full backup takes place once a day and takes about 30 minutes.
Transaction log backup takes palce every 10 minute
The discussed transaction time is about 50 minutes.
January 23, 2013 at 12:04 am
1) Included with the database backup and the all log backups that occur while it's running
2) Included with the database backup and the all log backups that occur while it's running
3) Included with the database backup and the all log backups that occur while it's running
Full backups do not have any effect on the log backups that occur. The full backup backs up enough of the transaction log so that it can be restored consistently.
A full backup does not mark where the next log backup should start from, a log backup always backs up from where the previous log backup finished up to current.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
January 23, 2013 at 12:25 am
Thanks
My Conclusion from you answer is that if I don't have to keep the transaction log backups that occurred since the transaction stared and prior to the full database backup, in order to be able to restore the database to a point in time if it fails after the backup was done and the transaction finished (all three cases ).
Is my conclusion correct?
January 23, 2013 at 12:50 am
Mostly.
You can restore the full, then any log backups. However, what happens if that full is damaged and won't restore? If you've deleted the log backups prior to it, then you won't have the option of restoring a previous full backup and rolling the logs forward.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
Viewing 4 posts - 1 through 3 (of 3 total)
You must be logged in to reply to this topic. Login to reply