From: Tom Lane <tgl@sss.pgh.pa.us>
To: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: IN, EXISTS or ANY?
Date: Mon, 29 Apr 2002 00:54:23 -0400
Message-ID: <17935.1020056063@sss.pgh.pa.us> (raw)
In-Reply-To: <web-1387383@davinci.ethosmedia.com>
References: <web-1387383@davinci.ethosmedia.com>
"Josh Berkus" <josh@agliodbs.com> writes:
> I was wondering if there is any difference in execution speed for the
> following three statements:
> WHERE case_id IN (SELECT case_id FROM case_clients
> WHERE matter_no = '123.122342');
> or:
> WHERE case_id = ANY (SELECT case_id FROM case_clients
> WHERE matter_no = '123.122342');
> or
> WHERE EXISTS ( SELECT case_id FROM case_clients
> WHERE matter_no = '123.122342'
> AND case_id = cases.case_id);
IN is the same as = ANY (cf. row_expr production in
src/backend/parser/gram.y for implementation, or SQL92 8.4 rule 4
for specification; there ain't *no* difference).
But EXISTS is an entirely different animal which is often faster
... isn't that in the FAQ?
regards, tom lane
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To: pgsql-sql@postgresql.org
Cc: tgl@sss.pgh.pa.us, josh@agliodbs.com
Subject: Re: IN, EXISTS or ANY?
In-Reply-To: <17935.1020056063@sss.pgh.pa.us>
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