SQL linked server twice as slow in Windows 7 as XP
928132Apr 3 2012 — edited Apr 16 2012We have a transaction based synchronization from SQL Server to Oracle, i.e. both must commit or rollback in one distributed transaction. We achieved this using MSSQL Linked Server using the Oracle Provider for OLE DB and triggers running openquery for speed.
The SQL Sever 2008 was on XP (doesn't need a server) and the Oracle 11g was on Red Hat 5EL. In testing from the first trigger firing to the last trigger finishing, a save test took ~11 Seconds, not perfect but acceptable. Yet when we moved to Windows 7 this time rose to 19 Seconds.
We contacted Microsoft support and they seen to thing it is a multi platform issue. So to prove them wrong we created an oracle DB on a Windows 7 system and ran the tests again, same issue. They will not look into the issue without us paying for premium support at an hourly rate, due to the Oracle DB. So we created one more test environment to try to prove it was a Microsoft issue and not an Oracle driver issue we created 2 SQL servers and ran tests to see if we got the same issue. We got the following results, which seems to point the finger at the Oracle OLE Driver on Win 7:
Windows XP sync to Windows 7:
SQL Server to Oracle = ~8 seconds
SQL Server to SQL Server = ~6.5 seconds
Windows 7 sync to Windows 7:
SQL Server to Oracle = ~19 seconds
SQL Server to SQL Server = ~5.5 seconds
Has anybody else found this issue and if so have they found a cause?
We Have run NetMon and analysed the results and the packets seem to take twice as long in Win 7 as Win XP. This seemed to point to a network issue, but does not explain why 100% Microsoft is faster when synchronising Win 7 to Win 7, as opposed to Win XP to Win 7.
I get the feeling the issue lies somewhere in the changes that were made by Microsoft in Vista in the networking protocols and configuration, causing a side affect in the OLE Driver. It could be that the driver works, but needs to be tuned with the new networking protocols from Microsoft.
We have tried countless network settings, even the ones suggestions from MS Support made no difference at all.
Edited by: 925129 on 03.04.2012 03:57
Corrected a couple of types