From: Tom Lane <tgl@sss.pgh.pa.us>
To: Fredrik Olsson <fredrik.olsson@treyst.se>
Cc: pgsql-performance@postgresql.org
Subject: Re: Force another plan.
Date: Sun, 19 Feb 2006 12:31:17 -0500
Message-ID: <11673.1140370277@sss.pgh.pa.us> (raw)
In-Reply-To: <43F866E2.20001@treyst.se>
References: <43F74592.7010701@treyst.se>
<20490.1140287811@sss.pgh.pa.us>
<43F866E2.20001@treyst.se>
Fredrik Olsson <fredrik.olsson@treyst.se> writes:
> -> Seq Scan on t_entities (cost=0.00..1.49 rows=7 width=4)
> (actual time=404.539..409.302 rows=2 loops=1)
> Filter: ((haveaccess(createdby, responsible, "class",
> false) OR CASE WHEN (partof = 'contacts'::name) THEN
> ischildof(ancestorof(me()), "ID") ELSE false END) AND (subplan))
> SubPlan
> -> Function Scan on alleventoccurances
> (cost=0.00..12.50 rows=1000 width=8) (actual time=27.871..27.871 rows=0
> loops=14)
This seems to be your problem right here: evaluating that subplan for
each row of t_entities is pretty expensive, and yet the planner's
estimating a total cost of only 1.49 to run the scan. What PG version
is this? AFAICT we've accounted for subplan costs in scan quals for
a long time, certainly since 7.4. Can you put together a self-contained
test case for this?
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, fredrik.olsson@treyst.se
Subject: Re: Force another plan.
In-Reply-To: <11673.1140370277@sss.pgh.pa.us>
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