sql server management studio 2008 sucks up with memory yielding .net runtime failure

Question

PROBLEM sql server management studio 2008 sucks up with memory yielding a .net runtime error. It crashes with an empty message in an error-dialog but there can be found a little eventlog entry, reading:

<EventData>
  <Data>.NET Runtime version 2.0.50727.5446 - Fatal error in the execution engine (7269AECA) (0).</Data> 
</EventData>

Original Eventlog Entry (German):

<EventData>
  <Data>.NET Runtime version 2.0.50727.5446 - Schwerwiegender Fehler im Ausführungsmodul (7269AECA) (0).</Data> 
</EventData>

RECREATING THE ERROR

After about every 10 Million-th Insert-Statement Management Studio 2008 executed in a loop against a remote instance of SQL Server 2005, the 4GB of memory on my dev-workstation are up which leads to the stated error above. Why the hell i'm executing insert-statements in a loop? - Since SQL Server doesn't allow one to set the actual TIMESTAMP of a DB manually, dummy-data-manipulation-statements are needed to help one out (the TIMESTAMP-manipulation-lock is no bad idea but on a dev-environment sometimes needed).

CREATE TABLE __DUMMY (I INT, TS TIMESTAMP)
DECLARE @FROM INT
DECLARE @TO INT
SET @FROM = 666
SET @TO = 666666666
WHILE (@FROM < @TO)
BEGIN
    INSERT INTO __DUMMY (I) VALUES(@FROM)
    SET @FROM = @FROM +1
END

On another session to SQL Server I truncate the __DUMMY-table from time to time:

SELECT @@DBTS, CONVERT(INT, @@DBTS), 'SERVER'
UNION
SELECT CONVERT(TIMESTAMP, 666666666), 666666666, 'CLIENT'

EXEC sp_spaceused '__DUMMY'
TRUNCATE TABLE __DUMMY

--writes    ~10.000 Tuple/Second
--allocates ~100.000 Byte/10.000 Tuple
--      ==> ~10 Byte/Tuple (are "roughly" made up of: INT = 4 BYTE, TIMESTAMP = 8 BYTE)
--insert/truncate is ~100.000 times more performant than doing a insert/delete in the loop or a permanent update on one tuple (haven't tried indices yet)

See http://www.flickr.com/photos/74806161@N03/6732847259/in/photostream for image showing sucker-process-descriptions and http://www.flickr.com/photos/74806161@N03/6732846981/in/photostream for image showing the memoryconsumption of the sucker-process

Anyone any Ideas?

Answer 1

Looks like up until SQL Server 2000 there was an undocumented command DBCC CHECKDBTS that did exactly what you want but it is no more. It looks like it is stored on the database boot page with no (safe, see below) way of manually setting it.

I'm not sure why you want to do this and I suggest that you don't bother but if you must then you will likely find set based inserts considerably quicker.

(NB: The below might need tweaking to avoid overshooting the target as I found that @@DBTS incremented by 1003921 for each million row insert but should be an improvement...)

CREATE TABLE __DUMMY (I TINYINT, TS TIMESTAMP)

DECLARE @Target INT, @Batch INT
SET @Target = 666666666

WHILE @Target >  CONVERT(INT, @@DBTS)
BEGIN
RAISERROR ('@@DBTS = %d',0,1,@@DBTS) WITH NOWAIT;

SET @Batch = @Target - CONVERT(INT, @@DBTS);

IF @Batch > 1000000 
    SET @Batch = 1000000;

   WITH E00(N) AS (SELECT 1 UNION ALL SELECT 1),
        E02(N) AS (SELECT 1 FROM E00 a, E00 b),
        E04(N) AS (SELECT 1 FROM E02 a, E02 b),
        E08(N) AS (SELECT 1 FROM E04 a, E04 b),
        E16(N) AS (SELECT 1 FROM E08 a, E08 b),
        E32(N) AS (SELECT 1 FROM E16 a, E16 b),
   cteTally(N) AS (SELECT ROW_NUMBER() OVER (ORDER BY N) FROM E32)
 INSERT INTO __DUMMY (I) 
  SELECT 1
   FROM cteTally
  WHERE N <= @Batch;


TRUNCATE TABLE __DUMMY
END


DROP TABLE __DUMMY

Or alternatively if this is only a development database, you have backups and you aren't going to come complaining to me if it all goes wrong you could do some experimenting with the undocumented and highly warned against DBCC WRITEPAGE command.

USE tempdb;

IF DB_ID('TestDBTS') IS NOT NULL
    DROP DATABASE TestDBTS;

CREATE DATABASE TestDBTS;

USE TestDBTS;

DBCC WRITEPAGE(TestDBTS, 1, 9, 412, 8, 0xAA86BC2700000000);

ALTER DATABASE TestDBTS SET OFFLINE WITH ROLLBACK IMMEDIATE;

ALTER DATABASE TestDBTS SET ONLINE WITH ROLLBACK IMMEDIATE;

USE TestDBTS;
SELECT @@DBTS;

DBCC TRACEON (3604);
DBCC DBINFO ('TestDBTS');
DBCC TRACEOFF (3604);

Answer 2

Do you have SET NOCOUNT ON in your script? If not SSMS is going to be getting back a lot of data which it needs to keep in memory.