Re: Trouble managing planner for timestamptz columns

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Marc Morin" <marc(at)sandvine(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Trouble managing planner for timestamptz columns
Date: 2006-03-10 23:40:40
Message-ID: 22202.1142034040@sss.pgh.pa.us
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"Marc Morin" <marc(at)sandvine(dot)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

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