Channel 9 Forums - Tech Off - SQL Server System Tables http://mschnlnine.vo.llnwd.net/d1/Dev/App_Themes/C9/images/feedimage.png Channel 9 Forums - Tech Off - SQL Server System Tables http://channel9.msdn.com/Forums Channel 9 keeps you up to date with the latest news and behind the scenes info from Microsoft that developers love to keep up with. From LINQ to SilverLight – Watch videos and hear about all the cool technologies coming and the people behind them. http://channel9.msdn.com/Forums en Mon, 20 May 2013 15:51:51 GMT Mon, 20 May 2013 15:51:51 GMT Rev9 4 -4 -1 Tech Off - SQL Server System Tables Just had an issue running sp_delete_backuphistory where the stored procedure would never complete (we left it run overnight). The stored procedure hadn't been run in a while on this server so the backupset and related tables were quite large (over 100,000 rows), after looking at the source of this stored procedure I have two comments/questions:

1. Why does this stored procedure use a cursor? As far as I can tell there is nothing in it that couldn't be done in set operations.

2. Why aren't there any useful indexes on the backupset table? Simply adding an index to backup_finish_date improved the speed of this stored procedure a huge amount.

]]> http://channel9.msdn.com/Forums/TechOff/5194-SQL-Server-System-Tables/5194#5194 Fri, 30 Apr 2004 00:07:26 GMT http://channel9.msdn.com/Forums/TechOff/5194-SQL-Server-System-Tables/5194#5194 wbarthol 4 http://channel9.msdn.com/Niners/wbarthol/Discussions/RSS Tech Off - SQL Server System Tables I have no good answer for either of these questions.
 
This has come up a couple of times in support cases and the solution has been a re-write of the SP, or a mixture of delete / truncate against the tables.

Hopefully you have a working solution you can use ( i presume indexing helped Smiley ) ? If not, let me know and i can forward you on a potential alternative...

]]> http://channel9.msdn.com/Forums/TechOff/5194-SQL-Server-System-Tables/fdca45dc0f684686acf99dea010f901d#fdca45dc0f684686acf99dea010f901d Fri, 30 Apr 2004 05:11:38 GMT http://channel9.msdn.com/Forums/TechOff/5194-SQL-Server-System-Tables/fdca45dc0f684686acf99dea010f901d#fdca45dc0f684686acf99dea010f901d spod 4 http://channel9.msdn.com/Niners/spod/Discussions/RSS Tech Off - SQL Server System Tables The indexing helps as long as you are still only deleting small batches, if you have a rewrite of the stored procedure you could easily send me that would save me some time in rewriting it myself (although it's not a particularly complicated proc).

]]> http://channel9.msdn.com/Forums/TechOff/5194-SQL-Server-System-Tables/d7a1724a985c4bfea2059dea010f9047#d7a1724a985c4bfea2059dea010f9047 Fri, 30 Apr 2004 05:35:23 GMT http://channel9.msdn.com/Forums/TechOff/5194-SQL-Server-System-Tables/d7a1724a985c4bfea2059dea010f9047#d7a1724a985c4bfea2059dea010f9047 wbarthol 4 http://channel9.msdn.com/Niners/wbarthol/Discussions/RSS Tech Off - SQL Server System Tables We had the identical situation occur using sp_delete_backuphistory on a 2.5 GB MSDB. Most of which was backup history.

Here's the way I've worked around the issue. Keep in mind that we blew away all history, because we simply don't use it, but you can augment the routine if you use backup history in any way. Then, you'll have to augment the code below to work for you.
 
Keep in mind this is not a Microsoft supported solution.

1.> To get started, get a base line of what's in those tables that you want to delete.

select count(*) from dbo.backupfile
select count(*) from dbo.backupmediafamily
select count(*) from dbo.backupmediaset
select count(*) from dbo.backupset
select count(*) from dbo.restorefile
select count(*) from dbo.restorefilegroup
select count(*) from dbo.restorehistory

2.> Now, Restore msdb to an alternate database. We restored to msdb1. Let SQL do it's thing unhindered by giving it msdb without your tinkering. You'll do the deletes on this database and then restore it back to msdb. Keep in mind that you don't want to create any new jobs that'll get erased when you restore this older, but smaller, msdb database.

3.> For the following tables check all the foreign key relationships and select cascade delete on every corresponding primary key.

Note, I tried to remove all relationships and truncate data from every table, but found that SQL would not let us add relationships back to the system tables. However, it will allow adding/removing the cadcade delete option.

4.> Once you're sure that you've added cascade delete to all those relationships, create a SQL job that runs the following statement.

use msdb1
delete from backupmediaset

5.> Run the job you just created and wait a while. Our delete took a little less than 3.5 hours for about 2.5 GB of backup history data.

6.> Let the job complete, backup msdb1, and restore to msdb.

I ran the following statements to oust connections to msdb so we could restore it. (lines are wrapping here)

alter database msdb set restricted_user with rollback immediate
go
RESTORE DATABASE [msdb]
FROM DISK=
's:\msdb1.bak'

WITH REPLACE,
move 'MSDBData' TO 'R:\Program Files\Microsoft SQL Server\MSSQL$I2KMCDC1\Data\msdbdata.mdf',
move 'MSDBLog' TO 'R:\Program Files\Microsoft SQL Server\MSSQL$I2KMCDC1\Data\msdblog.ldf'
Go

7.> After the restore, you'll notice the job you created to run the delete, disappears and that your msdb mdf file is much, much, smaller.

8.> Run the following to verify:

select count(*) from dbo.backupfile
select count(*) from dbo.backupmediafamily
select count(*) from dbo.backupmediaset
select count(*) from dbo.backupset
select count(*) from dbo.restorefile
select count(*) from dbo.restorefilegroup
select count(*) from dbo.restorehistory

9.> Remove all the cascade deletes from the backup/restore table relationships in msdb.

10.> I'm going to try to run sp_delete_backuphistory on a regular basis instead of waiting so long. Hopefully, we won't have to do this again.

***Keep your old original msdb backup copy around for a few weeks in case you discover any anomalies.


]]> http://channel9.msdn.com/Forums/TechOff/5194-SQL-Server-System-Tables/bd06f20bf3084018851d9dea010f9094#bd06f20bf3084018851d9dea010f9094 Fri, 07 May 2004 12:29:59 GMT http://channel9.msdn.com/Forums/TechOff/5194-SQL-Server-System-Tables/bd06f20bf3084018851d9dea010f9094#bd06f20bf3084018851d9dea010f9094 flotsam 4 http://channel9.msdn.com/Niners/flotsam/Discussions/RSS