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To: "Marc Morin" <marc@sandvine.com>
cc: pgsql-performance@postgresql.org
Subject: Re: Trouble managing planner for timestamptz columns 
In-reply-to: <2BCEB9A37A4D354AA276774EE13FB8C2BCC473@mailserver.sandvine.com> 
References: <2BCEB9A37A4D354AA276774EE13FB8C2BCC473@mailserver.sandvine.com>
Comments: In-reply-to "Marc Morin" <marc@sandvine.com>
	message dated "Fri, 10 Mar 2006 16:47:08 -0500"
Date: Fri, 10 Mar 2006 18:40:40 -0500
Message-ID: <22202.1142034040@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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"Marc Morin" <marc@sandvine.com> writes:
> Well this analyze just took 12 minutes...  Stats target of 100.
> # time psql xxx xxx -c "analyze elem_trafficstats_1"

Try analyzing just the one column, and try reducing its stats target to
10.  It does make a difference:

sorttest=# set default_statistics_target TO 100;
SET
Time: 0.382 ms
sorttest=# analyze verbose d10;
INFO:  analyzing "public.d10"
INFO:  "d10": scanned 30000 of 833334 pages, containing 3600000 live rows and 0 dead rows; 30000 rows in sample, 100000080 estimated total rows
ANALYZE
Time: 137186.347 ms
sorttest=# set default_statistics_target TO 10;
SET
Time: 0.418 ms
sorttest=# analyze verbose d10(col1);
INFO:  analyzing "public.d10"
INFO:  "d10": scanned 3000 of 833334 pages, containing 360000 live rows and 0 dead rows; 3000 rows in sample, 100000080 estimated total rows
ANALYZE
Time: 17206.018 ms
sorttest=#

			regards, tom lane