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Old 03-15-10, 11:03
Rebecca Johnston Rebecca Johnston is offline
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Memory Issue SQl Server 2005

Hello,
I have a 2005 server that did have 4gb of memory. We upgraded to 8gb because the server stats were showing that 97% of memory was being used. After the upgrade to 8gb we are still showing 97% of memory being used.
The stats show that SQL is using 6,697 mb of it. Of that the buffer cache has 6,694 mb of active pages.
Is this common or should I look for ways to reduce the cache?
We are running SQL Server 9.00.3077.00 SP2 Enterprise Edition (64-bit)

Thanks for you help and advice

Rebecca
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Old 03-15-10, 11:30
MCrowley MCrowley is offline
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Left to its own devices, SQL Server will use as much memory as you give it. Are you having errors related to memory, or seeing high disk read/write activity?
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Old 03-15-10, 11:35
Rebecca Johnston Rebecca Johnston is offline
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the disk(s) are busy only about 4% of the time. Two local disks and San storage. The average disk queue length is about 1.
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Old 03-15-10, 11:40
pootle flump pootle flump is offline
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Yes, SQL Server is optimised to retain as much in cache as possible. Why write a page to disk and clear the cache only to risk having to read it back again any second? Unused memory isn't really any use to it. It only flushes the cache when there is pressure to do so, or you instruct it to.
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Old 03-15-10, 11:44
Rebecca Johnston Rebecca Johnston is offline
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So is it wise to just let things run as they are? I haven't noticed any performace issues but the memory being used by the buffer cache was rasing a red flag in my mind.
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Old 03-15-10, 12:05
pootle flump pootle flump is offline
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The best measure of memory pressure in SQL Server is not how much SQL Server is using but how often a request cannot be met by what is in the cache. Look at the Buffer Hit Cache Ratio % in perfmon. Or you could just keep buying RAM until you have enough to store all your databases in memory
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