Hi,
I'm running a cursor (I know not quit good...but). For I don't know why, in one night the execution time step from 1h30 to 3h. I restore my database on a TEST Server (same version), the the execution time is still 1h30...
I monitored both execution, and realise that the CPU time for the CXPACKET process is 4 time higher it the PRODUCTION server than on the TEST Server....
Do you think that can be the problem?
From Neil Pike's FAQ
Q. What does a wait type of CXPacket or Exchange mean?
A. You will get this only with versions of SQL that support parallel queries, i.e. SQL 7 and later. It means that one thread of the query is waiting for a message packet from another, and the one it is waiting on is either blocked by a traditional
cause or has hit some sort of parallelism bug.
CXPacket means it is waiting on a data packet - i.e. the results of an internal query is being passed. Exchange means that it is waiting on a control packet - i.e. waiting for a child/sibling process to tell you that it is finished.
If the query doesn't complete then make sure the latest service pack is applied as there are several parallel query fixes in each one. If it still doesn't fix it then you have run into an unfixed bug and will need to contact Microsoft PSS and raise a bug
report. You should be able to work-around the problem by adding (MAXDOP=1) as a query hint which will prevent the query being parallelized.
Mark Allison, SQL Server MVP
http://www.markallison.co.uk
Showing posts with label restore. Show all posts
Showing posts with label restore. Show all posts
Sunday, March 25, 2012
Cursor Faster in a TEST Server than on a PROD Server
Hi,
I'm running a cursor (I know not quit good...but). For I don't know why, in
one night the execution time step from 1h30 to 3h. I restore my database o
n a TEST Server (same version), the the execution time is still 1h30...
I monitored both execution, and realise that the CPU time for the CXPACKET p
rocess is 4 time higher it the PRODUCTION server than on the TEST Server...
.
Do you think that can be the problem?From Neil Pike's FAQ
Q. What does a wait type of CXPacket or Exchange mean?
A. You will get this only with versions of SQL that support parallel
queries, i.e. SQL 7 and later. It means that one thread of the query is wait
ing for a message packet from another, and the one it is waiting on is eithe
r blocked by a traditional
cause or has hit some sort of parallelism bug.
CXPacket means it is waiting on a data packet - i.e. the results of an inter
nal query is being passed. Exchange means that it is waiting on a control pa
cket - i.e. waiting for a child/sibling process to tell you that it is finis
hed.
If the query doesn't complete then make sure the latest service pack is appl
ied as there are several parallel query fixes in each one. If it still doesn
't fix it then you have run into an unfixed bug and will need to contact Mic
rosoft PSS and raise a bug
report. You should be able to work-around the problem by adding (MAXDOP=1) a
s a query hint which will prevent the query being parallelized.
Mark Allison, SQL Server MVP
http://www.markallison.co.uk
I'm running a cursor (I know not quit good...but). For I don't know why, in
one night the execution time step from 1h30 to 3h. I restore my database o
n a TEST Server (same version), the the execution time is still 1h30...
I monitored both execution, and realise that the CPU time for the CXPACKET p
rocess is 4 time higher it the PRODUCTION server than on the TEST Server...
.
Do you think that can be the problem?From Neil Pike's FAQ
Q. What does a wait type of CXPacket or Exchange mean?
A. You will get this only with versions of SQL that support parallel
queries, i.e. SQL 7 and later. It means that one thread of the query is wait
ing for a message packet from another, and the one it is waiting on is eithe
r blocked by a traditional
cause or has hit some sort of parallelism bug.
CXPacket means it is waiting on a data packet - i.e. the results of an inter
nal query is being passed. Exchange means that it is waiting on a control pa
cket - i.e. waiting for a child/sibling process to tell you that it is finis
hed.
If the query doesn't complete then make sure the latest service pack is appl
ied as there are several parallel query fixes in each one. If it still doesn
't fix it then you have run into an unfixed bug and will need to contact Mic
rosoft PSS and raise a bug
report. You should be able to work-around the problem by adding (MAXDOP=1) a
s a query hint which will prevent the query being parallelized.
Mark Allison, SQL Server MVP
http://www.markallison.co.uk
Sunday, February 19, 2012
CTP version and release version
we have a backup of a database from a release version with version number 9.00.1399 and we wanted to restore it to a server with version number (9.00.1116) CTP release. we were issued a version incopatibility message. is it possible to backup from a 9.00.1399 release with a backup file compatible for a CTP release, is there an available option during backup? thanks!
CTP versions are no longer supported. You should be using the released version of the product.
Ideally, you should be at SP1, as we fixed quite a few bugs there.
Backup is a physical operation. If the structure of the database pages has changed in any way, we have no way to do the conversion during restore. For moving up, we have the logic in the startup code to re-apply the same changes that the upgrade would do. We don't support moving down in versions where the database format is incompatible.
|||thanks kevin
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