Re: performance question (something to do w/ parameterized - Mailing list pgsql-performance

From Tom Lane
Subject Re: performance question (something to do w/ parameterized
Date
Msg-id 2398.1147129561@sss.pgh.pa.us
Whole thread Raw
In response to Re: performance question (something to do w/ parameterized  (Jeffrey Tenny <jeffrey.tenny@comcast.net>)
Responses Re: performance question (something to do w/ parameterized  (Jeffrey Tenny <jeffrey.tenny@comcast.net>)
List pgsql-performance
Jeffrey Tenny <jeffrey.tenny@comcast.net> writes:
> I tried the seqscan disabling and got what sounds like the desired plan:
> Sort  (cost=54900.62..54940.29 rows=1587 width=16) (actual time=20.208..22.138 rows=677 loops=1)
>     Sort Key: f, c
>     ->  Index Scan using x_f_idx, x_f_idx, ...
>     (cost=0.00..54056.96 rows=1587 width=16) (actual time=1.048..15.598 rows=677 loops=1)
>     Index Cond: ((f = 1) OR (f = 2) OR (f = 3) ....

Hm, vs 35000 or so estimates for the slower plans.  My recommendation
would be to decrease random_page_cost to 2 or so, instead of the brute
force disable-seqscans approach.

            regards, tom lane

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