Message-ID: <50FD5EDE.8010002@comcast.net>
Date: Mon, 21 Jan 2013 10:29:34 -0500
From: AJ Weber <aweber@comcast.net>
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To: pgsql-performance@postgresql.org
Subject: Analyze and default_statistics_target
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I was under the impression that the default_statistics_target was a 
percentage of rows to analyze.  Maybe this is not the case?

I ran an analyze during a "quiet point" last night and for a few of my 
large tables, I didn't get what I consider a reasonable sampling of 
rows.  When running with "verbose" enabled, it appeared that a maximum 
of 240000 rows were being analyzed, including on tables exceeding 4-8mm 
rows.  My default_statistics_target = 80.

Shouldn't I be analyzing a larger percentage of these big tables?

What is the unit-of-measure used for default_statistics_target?

Thanks in advance,
AJ


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