March 27, 2010 at 9:48 pm
Hi,
We enabled the below Trace flags as suggested by MS to investigate a sql dump last year when we are on SQL Server 2005 with SP2 and Max memory was NOT set. Later, we applied SP3 & set Max memory and we never get that error again. But the trace flags enabled were still there as startup parameters.
T 815
-T 818
-T 2551
I’m wondering whether enabling these trace flags will impact SQL Server performance?
Thanks
March 28, 2010 at 2:15 am
Mani-584606 (3/27/2010)
Hi,We enabled the below Trace flags as suggested by MS to investigate a sql dump last year when we are on SQL Server 2005 with SP2 and Max memory was NOT set. Later, we applied SP3 & set Max memory and we never get that error again. But the trace flags enabled were still there as startup parameters.
T 815
-T 818
-T 2551
I’m wondering whether enabling these trace flags will impact SQL Server performance?
Thanks
815 enables memory latch enforcement
818 helps detect stale reads
2551 is used to produce a full-filtered memory dump instead of a minidump
815 (particularly) and 818 will both affect performance. You should remove them. See SQL Server I/O Basics for full details.
2551 is only needed to provide extra information to CSS in the event of a handled exception inside SQL Server. It can be safely removed.
March 28, 2010 at 12:06 pm
815 (particularly) and 818 will both affect performance. You should remove them. See SQL Server I/O Basics for full details
I went through the document but I did not find how these trace flags effects performance and how much impact it will have on performance?
thanks
March 28, 2010 at 8:27 pm
Mani-584606 (3/28/2010)
815 (particularly) and 818 will both affect performance. You should remove them. See SQL Server I/O Basics for full details
I went through the document but I did not find how these trace flags effects performance and how much impact it will have on performance?
There are several references like the following:
The [815] trace flag should only be used under the direction of Microsoft SQL Server Support as it can have significant performance ramifications
All three flags are intended for trouble-shooting - once the problem has been resolved it is recommended that you turn them off again.
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