Re: IN vs EXISTS equivalence

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
Cc: pgsql-hackers(at)postgresql(dot)org, "<Simon Riggs" <simon(at)2ndquadrant(dot)com>
Subject: Re: IN vs EXISTS equivalence
Date: 2008-08-04 23:48:12
Message-ID: 15026.1217893692@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

"Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov> writes:
> I'm adding some NOT EXISTS examples to the thread for completeness of
> what someone might want to address while working on it. For two
> queries which can easily be shown (to a human viewer, anyway) to
> return identical results, I see performance differences of over five
> orders of magnitude.

Could we see EXPLAIN ANALYZE not just EXPLAIN for these? When people
are complaining of bad planner behavior, I don't find bare EXPLAIN
output to be very convincing.

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2008-08-05 00:02:03 Re: Automatic Client Failover
Previous Message Dimitri Fontaine 2008-08-04 23:41:12 Re: Automatic Client Failover