The Issue
I've been running a particularly large query, generating millions of records to be inserted into a table. Each time I run the query I get an error reporting that the transaction log file is full.
I've managed to get a test query to run with a reduced set of results and by using SELECT INTO instead of INSERT into as pre built table. This reduced set of results generated a 20 gb table, 838,978,560 rows.
When trying to INSERT into the pre built table I've also tried using it with and without a Cluster index. Both failed.
Server Settings
The server is running SQL Server 2005 (Full not Express).
The dbase being used is set to SIMPLE for recovery and there is space available (around 100 gb) on the drive that the file is sitting on.
The transaction log file setting is for File Growth of 250 mb and to a maximum of 2,097,152 mb.
The log file appears to grow as expected till it gets to 4729 mb.
When the issue first appeared the file grow to a lower value however i've reduced the size of other log files on the same server and this appears to allow this transaction log file grow further by the same amount as the reduction on the other files.
I've now run out of ideas of how to solve this. If anyone has any suggestion or insight into what to do it would be much appreciated.
First, you want to avoid auto-growth whenever possible; auto-growth events are HUGE performance killers. If you have 100GB available why not change the log file size to something like 20GB (just temporarily while you troubleshoot this). My policy has always been to use 90%+ of the disk space allocated for a specific MDF/NDF/LDF file. There's no reason not to.
If you are using SIMPLE recovery SQL Server is supposed manage the task of returning unused space but sometimes SQL Server does not do a great job. Before running your query check the available free log space. You can do this by:
right-click the DB > go to Tasks > Shrink > Files.
change the type to "Log"
This will help you understand how much unused space you have. You can set "Reorganize pages before releasing unused space > Shrink File" to 0. Moving forward you can also release unused space using CHECKPOINT; this may be something to include as a first step before your query runs.
Related
I run a query in which I wanted to update more then 130 mln of records. After few hours I got an error:
The transaction log for database 'MGR' is full due to 'ACTIVE_TRANSACTION'.
now I ve got 70 MB free on my C disk drive.
I supose that the problem was with to little disc space and thats why query failed but how can I now regain the lost disc space from before query ?
Im using sql server 2008 R2
Thanks for any hints
The problem has to do with how sql logs all the changes during an active transaction. While a transaction is active, the log cannot be flushed, so if you have a huge active transaction the log keeps growing until it reaches a point where it can exceed its capacity. The amount of logging depends on many factors: the recovery mode (full recovery mode is the one that generates more logging activity). Also, you can breakdown the transaction in small chunks to enable log flushing in between. Also look into table hint TABLOCK. The lost amount of disk must possibly have gone to the log file. Check that out.
This question already has answers here:
How do I shrink my SQL Server Database?
(16 answers)
Closed 8 years ago.
I'm facing a strange problem about a staging database used by my ETL (to update rows).
Only rows to update are stored in the database, then a script is executed to update the destination database. At the end of the process, It truncates the staging database.
It removes all data, however the allocated size for my database grows every execution time of my SSIS package. So, is there a way to reduce the allocated size and to limit the maximum allocated size ? In SQL Server Management Studio, there is a wizard to reduce data size and database size.
Is there the same command in T-SQL ?
Thanks !
Don't.
If your staging needs a database of size X, then size the database at X and leave it so. Attempting to shrink it is misguided at best. By shrinking it all you achieve is just invite an opportunity for your ETL to fail tomorrow, because it runs out of required disk space. Do not fool yourself that 'I only need space X for ETL'. You need space X, period.
I'm not even going to go into all the performance problems related to shrink and re-growth.
There is a command in T-SQL.
Look here [http://msdn.microsoft.com/de-de/library/ms189493.aspx][1]
DBCC SHRINKFILE (Transact-SQL): Shrinks the size of the specified data or log file for the current database, or empties a file by moving the data from the specified file to other files in the same filegroup, allowing the file to be removed from the database. You can shrink a file to a size that is less than the size specified when it was created. This resets the minimum file size to the new value.
But take the answer from Remus in consideration
I am moving around 10 million data from one table to another in SQL Server 2005. The Purpose of Data transfer is to Offline the old data.
After some time it throws an error Description: "The LOG FILE FOR DATABASE 'tempdb' IS FULL.".
My tempdb and templog is placed in a drive (other than C drive) which has around 200 GB free. Also my tempdb size in database is set to 25 GB.
As per my understanding I will have to increase the size of tempdb from 25 GB to 50 GB and set the log file Auto growth portion to "unrestricted file growth (MB)".
Please let me know other factors and I cannot experiment much as I am working on Production database so can you please let me know if they changes will have some other impact.
Thanks in Advance.
You know the solution. Seems you are just moving part of data to make your queries faster.
I am agree with your solution
As per my understanding I will have to increase the size of tempdb from 25 GB to 50 GB and set the log file Auto growth portion to "unrestricted file growth (MB)".
Go ahead
My guess is that you're trying to move all of the data in a single batch; can you break it up into smaller batches, and commit fewer rows as you insert? Also, as noted in the comments, you may be able to set your destination database to SIMPLE or BULK-INSERT mode.
Why are you using Log file at all? Copy your data (Data and Logfile) then set the mode on SIMPLE and run the transfer again.
I have a database that's taking up nearly 7 gigs. If I look at the table usage, it should be much less than that, like 40 megs. There was a large log table that I deleted yesterday, but my database still says it's very large.
Here are the stats:
database_name database_size unallocated space
Umbraco_Indoorpower 6911.56 MB 859.59 MB
reserved data index_size unused
31144 KB 26272 KB 3240 KB 1632 KB
I ran this:
DBCC SHRINKDATABASE (umbraco_indoorpower, 99);
And that got my database down to 2.3 gigs. Still though, way too large.
database_name database_size unallocated space
Umbraco_Indoorpower 2302.44 MB 1.63 MB
reserved data index_size unused
30016 KB 26200 KB 3240 KB 576 KB
I'm guessing I'm not freeing up all the space from that log table that I deleted yesterday. I actual ran delete from tblLog. Maybe that was the wrong way to go about it.
Does anyone know how I can free up some more space?
How big is the log file? What is your recovery model? It's quite possible that the database_size number above is nearly 7 GB of log and very little data. Find the files on your hard drive - you can locate the paths using:
EXEC umbraco_indoorpower..sp_helpfile;
I am going to bet that the LDF is HUGE and the MDF is actually small. In which case you are probably in FULL recovery model and have never taken a log backup. If this is true then you can do this:
USE umbraco_indoorpower;
GO
BACKUP LOG umbraco_indoorpower TO DISK = 'C:\some_path\umbraco.trn';
GO
DBCC SHRINKFILE(umbraco_indoorpower_log, 20); -- guessing on target MB size here
(If you are in simple recovery model, the above will fail, but there will be some other explanation why the log file is large - e.g. a long-running or uncommitted transaction, did your delete commit?)
Then you will want to either (a) set up proper maintenance, including full/diff/log backups, which will help make optimal reuse of the log file, or (b) switch to simple recovery, in which case the log will manage itself.
In most cases simple recovery does not provide enough protection in the event of a disaster, but that is for you to decide.
In the meantime, you can shrink the file all you want, but if you keep your recovery model and transaction handling the way it is, you'll just be seeing your file grow again and you'll be back tomorrow running the shrink command. This is absolutely horrible for your files. This is why I object to answers like "Run a shrink operation." I talk about why here:
Oh, the horror! Please stop telling people they should shrink their log files!
http://www.brentozar.com/archive/2009/08/stop-shrinking-your-database-files-seriously-now/
In any case, you have data and log, and for the log to be shrunk, you would have to have made a backup.
Edit: Everything Aaron said
The existing answers are already pretty good. I have one additional solution: Script the database including data (the SSMS UI allows you to do this easily) and execute the script in a fresh database.
You maybe want to switch to simple log model, too (if you don't have a special need for using the full logging model). One thing is for sure: You can't run in full mode and not have proper transaction log management.
Another thing that can take up more space in SQL Server is Service Broker queues. In my case I have 6 million rows in queues taking up 17GB...
Im deploying my db, i more or less emptied the db(data) and then created a backup.
the .bak file is over 100mb.
why is this?
how do i get it down?
im using sql server 2008
EDIT
When you back up, please note that SQL Server backup files can contain multiple backups. It does not overwrite by default. If you choose the same backup file and do not choose the overwrite option, it simply adds another backup to the same file. So your file just keeps getting larger.
Run this and all will be revealed:
select dpages *8 [size in kbs]
from sysindexes
where indid <= 1
order by 1 desc
You can also..
Do two backups in a row to have the 2nd backup contain minimal log data. The first backup will contain logged activity so as to be able to recover. The 2nd one would no longer contain them.
There is also an issue with leaked Service Broker handles if you use SSSB in your database with improper code, but if this is the case, the query above will reveal it.
To get the size down, you can use WITH COMPRESSION, eg.
backup database mydb to disk = 'c:\tempdb.bak' with compression
It will normally bring it down to about 20% the size. As Martin has commented above, run also
exec sp_spaceused
To view the distribution of data/logs. From what you are saying, 1.5 MB for first table... down to 8kB on the 45th row, that accounts for maybe tens of MB, so the rest could be in the log file.