November 4, 2014 at 8:19 am
Hi I have a 3rd party vendors DB on full recovery with regualr full backups and tran log backups.
I removed the shrinkDB from the daily full backup plan because of the index fragmentation problems it causes.
There is an idea that because shrinkDB is not running, the transaction Log is growing too large.
Currently the data file is 50% free space of Total 9GB, an archive operation (huge delete) is periodically performed on it. The Tran log Now is about 3GB about 95% free space. I think the tran log is getting to 3GB because of this archive operation i.e. huge delete. However it is steady at 3GB
My attitude is to leave it as it is, eventually the 9GB will be used up, it grew from original 6GB in reasonable chunks so the disk is not fragmented. MS SQL server needed at 3GB tran log (grown from 1GB) at one stage so why make it grow again if we always shrink it
Will a large Tran log which is almost all free space affect performance as opposed to a smaller file with less free space?
There are quite alot of VLFs, so I guess it could do with a shrink and a resize to reduce the number of VLFs.
November 4, 2014 at 8:52 am
If you're backing up the transaction log then SQL Server should start reusing the space in the log file after the backup has finished. You could shrink the log file separately from the database file but as you say it'll only grow again and if you don't desperately need the disc space for something else then I wouldn't bother.
It's actually less efficient to have a smaller transaction log file because it takes time to grow it and that'll delay your operation while it's grabbing more disc space.
Not sure what you mean by VLF's though.
November 4, 2014 at 8:59 am
Kimberly Tripp describes VLF's in detail in this article
http://www.sqlskills.com/blogs/kimberly/transaction-log-vlfs-too-many-or-too-few/
Michael L John
If you assassinate a DBA, would you pull a trigger?
To properly post on a forum:
http://www.sqlservercentral.com/articles/61537/
November 4, 2014 at 9:08 am
Thanks for that, I'll have a look at those articles later. Still had to do some googling to find out what VLF stands for though, as she doesn't give a definition anywhere in the article!
November 4, 2014 at 9:20 am
Thanks Daniel that's what I was thinking. Virtual Log Files, see the article
Michael that's where I read about VLFs, don't pretend to understand everything, but I can see our tran log has grown in too small increments. Perhaps it's the same article or linked to Kimberley's shows performance update/inserts slows if VLFs are too small. I couldn't resize it as last VLF was still active, but I could now as active part has rolled around.
November 4, 2014 at 9:33 am
SSC Stairways:
http://www.sqlservercentral.com/stairway/73776/
Greg Larson on SimpleTalk
Michael L John
If you assassinate a DBA, would you pull a trigger?
To properly post on a forum:
http://www.sqlservercentral.com/articles/61537/
November 4, 2014 at 10:02 am
Michael L John (11/4/2014)
http://www.sqlservercentral.com/stairway/73776/
Greg Larson on SimpleTalk
Michael L John (11/4/2014)
http://www.sqlskills.com/blogs/kimberly/transaction-log-vlfs-too-many-or-too-few/%5B/quote%5D
Just making the links easier to use for others:
http://www.sqlservercentral.com/stairway/73776/
http://www.sqlskills.com/blogs/kimberly/transaction-log-vlfs-too-many-or-too-few/
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