January 13, 2009 at 10:07 am
I've got a 2000 SP4 Sql Server (32 bit) sitting on top of Win 2003 SP2 (64 bit) and something does not make sense. Generally, when I look at Perf Mon throughout the day on this server, I see a good Buffer Cache Hit Ratio, i.e. around 99%, but a Page Life Expectancy < 150. Doesn't the former mean we have plenty of memory and the latter mean we don't have enough memory? Which counter do I trust? Shouldn't I be seeing lower Buffer Cache Hit Ratio numbers in, say, the 90's and 80's with that low of Page Life Expectancy??
January 16, 2009 at 3:48 pm
You need to monitor both the counters during the same time period. Also, we need to know total memory on box, memory set aside for sql server.
MJ
January 16, 2009 at 4:32 pm
Keep in mind also that the buffer cache hit rate is cummulative from the last restart of the SQL service. PLE consistantly less than 300 is a sign of memory pressure.
January 16, 2009 at 7:49 pm
Hi,
We want to set max memory size to 12GB out of 16 GB RAM. I set the max memory 12 GB and restart the server, immediately I can see that the procudre cache is down to 68% in monitoring tool?
So as you said buffer cache is cumulative, the procedure cash aslo cumulative?
After restarting the service, in general how the produdure cash value will be?
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