RE: Optimizer not using histogram to calculate estimated number of rows?

From: Allen, Brandon <>
Date: Wed, 10 Jun 2009 16:19:43 -0700
Message-ID: <64BAF54438380142A0BF94A23224A31E1126E73473_at_ONEWS06.oneneck.corp>

I wouldn't consider "over 100 rows" vs "3 rows" to be "highly skewed" in relation to a total of 166,067 rows. You're talking about .0006% of the table vs. .0018% of the table - a very small percentage either way, and .0018%, or 100 rows, probably isn't nearly enough to warrant a full scan instead of an index scan if that's what you have in mind. Is that what you had in mind?

You might want to test with a FULL() hint to see just how much worse the performance is with a full scan.


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Received on Wed Jun 10 2009 - 18:19:43 CDT

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