Differential backups are huge compared to full backups

[sqlcasey]

Hello,

Just recently I noticed that on one of our databases, the diff backups are HUGE compared to the full backups.

For example, the regular full backup is only 80 MB, however the diff backups are 800 MB to 1.2 GB in size. The activity on this database is low. Our other databases are not exhibiting this anomaly, whereas they have much higher activiity.

Is there any logical explanation for this? How I can see what's going on with the diff backups?

Thanks much

 

[Catadmin]

How often are you doing the differentials on this database compared to the differential backups on the other databases?



Catadmin - MCDBA, MCSA
"No, no. Yes. No, I tried that. Yes, both ways. No, I don't know. No again. Are there any more questions?"
-- Xena, "Been There, Done That"

 

[SQLBill]

As I have had it explained to me....a differential backup contains ALL of the changes since 1) the last full backup or 2) the last differential, if doing multiple differential backups.

So, you insert a row, then you update the row, then you delete it. The diff backup will have ALL THREE of those transactions.

-SQLBill

Posting advice: FAQ481-4875

 

[sqlcasey]

Using RESTORE FILELISTONLY I saw that I was backing up the wrong database - duh

 

[Catadmin]

Hee. I have so done that before myself. @=)

Glad you figured out the problem.


Catadmin - MCDBA, MCSA
"No, no. Yes. No, I tried that. Yes, both ways. No, I don't know. No again. Are there any more questions?"
-- Xena, "Been There, Done That"