Re: Comparing Top 5 Timed Events and Cache Advisory

From: John Hurley <>
Date: Thu, 16 Jun 2011 10:34:16 -0700 (PDT)
Message-ID: <>


# This database is running batch processing. We are trying to justify
purchasing more memory.

In general improving batch processing times by throwing memory at the database instance is not a very effective approach. Might get 20 or 30 percent improvement for some parts ( shot in the dark ).

Much more effective in general is looking at the SQL being run in the batch and attacking the ( top ) bad performing parts of the batch runs. Reducing logical IOs will lead you to a reduction in physical IOs.

# The question is: how much improvement in batch run time we'll get if
we double memory size? 25%? 50%?

Well the cache advisory does give you a "reasonably accurate" guess at how many physical IOs you may save by increasing memory. That is an aggregate though ... and 10046 tracing and resource profiling of the relevant batch runs would eventually get you closer to a better guesstimate. Received on Thu Jun 16 2011 - 12:34:16 CDT

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