Backup scenario

Question

Backup scenario

y.koteswarrao-652921

SSCrazy

Points: 2010
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July 15, 2010 at 10:15 am

#226831

Hi,
If we schedule the backup as per below scenario
Full backup already exists
New Schedule
____________
Full backup -12.00 PM
Differential Backup -12.00PM
T-log Backup -12.00PM
In this scenario whether the differential backup start backup from already exist full backup or takes from the scheduled full backup.
Could any clarify me...
Koteswar rao

Viewing 10 posts - 1 through 9 (of 9 total)

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Gail Shaw SSC Guru Points: 1004504 More actions · Answer 1

Why schedule the diff at the same time as the full?

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

We walk in the dark places no others will enter
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y.koteswarrao-652921 SSCrazy Points: 2010 More actions · Answer 2

y.koteswarrao-652921

SSCrazy

Points: 2010

July 15, 2010 at 11:18 am

#1193652

This is asked by an interviewer

jvanderberg SSCertifiable Points: 6762 More actions · Answer 3

Short answer: You wouldn't do this. It's rediculous.

Long answer: What?

Steve Jones - SSC Editor SSC Guru Points: 736212 More actions · Answer 4

Makes no sense to me. A diff is used to reduce recovery time from logs and speed the backup impact since it should be shorter than a full. However since it depends on a full, this doesn't make sense. You might get it done slightly faster than the diff, but you'd need the previous full to recover with it.

If it took longer, then you'd be recovering to essentially the same time as this full, AND you'd need this full.

jvanderberg SSCertifiable Points: 6762 More actions · Answer 5

This may have been a trick question where they were actually looking for you to tell them that this is a undesirable backup solution (for several reasons). Or, perhaps as managers they just don't know enough to know how absurd this scenario is. Either way, knowing enough about differential backups to tell them that this isn't something you would ever do would probably be enough to satisfy the question.

--J

Ray Mond SSCertifiable Points: 7159 More actions · Answer 6

In this scenario whether the differential backup start backup from already exist full backup or takes from the scheduled full backup.

LOL. It depends. Both types of backups will block each other, and won't run simultaneously, so if SQL Server decided to perform the full backup first, the differential will start backing up all changes made after that backup. If SQL Server decided to perform the differential backup first, then it'll back up all changes made since the previous full backup.

SQL BAK Explorer - read SQL Server backup file details without SQL Server.
Supports backup files created with SQL Server 2005 up to SQL Server 2017.

shravani.gandhey Newbie Points: 3 More actions · Answer 7

The information provided by me is not clear.Could you please expalain me clearly?

prakskarry SSC Veteran Points: 202 More actions · Answer 8

It was a tricky question to see how much you know about backup/restore.It does not make any sense to have full & diff backup scheduled on same time.

Steve Jones - SSC Editor SSC Guru Points: 736212 More actions · Answer 9

shravani.gandhey (7/20/2010)
The information provided by me is not clear.Could you please expalain me clearly?

What's not clear? Are you talking to the OP or people who answered?

"Provided by me" means that you, shravani, gave information. "To" would be something explained to you. It doesn't make sense as this is your first post.