Click here to monitor SSC
SQLServerCentral is supported by Red Gate Software Ltd.
Log in  ::  Register  ::  Not logged in
Home       Members    Calendar    Who's On

Add to briefcase

Full backup not emptying transaction log Expand / Collapse
Posted Thursday, November 8, 2012 6:39 AM


Group: General Forum Members
Last Login: Wednesday, September 23, 2015 7:50 AM
Points: 21, Visits: 332
I have a database that process a lot of transaction late at night. It is set to full recovery mode. Every night I do a full backup of the database, but the log file does not empty out. It just continues to grow and never seems to release old transactions after a backup. As a quick fix, which i don't like, I will temporarily switch recovery mode to simple->truncate log file->set recovery mode to full->then full backup of database. Any ideas why the transaction log does not empty out after a full backup and continues to grow?

Post #1382464
Posted Thursday, November 8, 2012 6:47 AM



Group: General Forum Members
Last Login: Today @ 8:49 AM
Points: 5,376, Visits: 5,356
A full backup doesn't backup the transaction log, you need to take regular transaction log backups to make the log re-usable and stop it from growing out of control.

Managing Transaction Logs -

Stairway to Transaction Log Management -

Want an answer fast? Try here
How to post data/code for the best help - Jeff Moden
Need a string splitter, try this - Jeff Moden
How to post performance problems - Gail Shaw
CrossTabs-Part1 & Part2 - Jeff Moden
SQL Server Backup, Integrity Check, and Index and Statistics Maintenance - Ola Hallengren
Managing Transaction Logs - Gail Shaw
Troubleshooting SQL Server: A Guide for the Accidental DBA - Jonathan Kehayias and Ted Krueger

Post #1382467
Posted Thursday, November 8, 2012 7:03 AM
SSChasing Mays

SSChasing MaysSSChasing MaysSSChasing MaysSSChasing MaysSSChasing MaysSSChasing MaysSSChasing MaysSSChasing Mays

Group: General Forum Members
Last Login: Wednesday, September 2, 2015 9:34 AM
Points: 652, Visits: 1,435
I recommend you read Paul Randal's blog about backup myths:

30-05) a full or differential backup clears the log

No. A log backup includes all the log since the last log backup - nothing can change that - no matter whether that log was also backed up by a full or differential backup. I had a famous argument on Twitter last year and wrote this blog post as proof: Misconceptions around the log and log backups: how to convince yourself. In the FULL or BULK_LOGGED recovery models, the *only* thing that clears the log is a log backup.

Post #1382472
Posted Thursday, November 8, 2012 9:11 AM



Group: General Forum Members
Last Login: Today @ 7:17 AM
Points: 43,096, Visits: 40,087
If you're not taking log backups for point-in-time restore capability, why is the DB in full recovery model in the first place?

Gail Shaw
Microsoft Certified Master: SQL Server, MVP
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

Post #1382561
« Prev Topic | Next Topic »

Add to briefcase

Permissions Expand / Collapse