From: Jesper Krogh <jesper@krogh.cc>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Aaron Bono <postgresql@aranya.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: The empty list?
Date: Fri, 03 Nov 2006 07:46:13 +0100
Message-ID: <454AE5B5.4050106@krogh.cc> (raw)
In-Reply-To: <26899.1162535774@sss.pgh.pa.us>
References: <454A654B.2000306@krogh.cc>
<21991.1162506863@sss.pgh.pa.us>
<bf05e51c0611021443q27b1012bt9236ca595e1f03c2@mail.gmail.com>
<454ADB6F.9070602@krogh.cc>
<26899.1162535774@sss.pgh.pa.us>
Tom Lane wrote:
> Jesper Krogh <jesper@krogh.cc> writes:
>> ... the right-hand-side of on
>> in operation will allways be a list (if I havent forgotten something).
>
> IN (SELECT ...) for one thing.
Isn't that "just" a list of rows(complex value) instead of an list of
types(simple values)?
>> ... but missing SQL for the empty list basically means that
>> we cant handle the empty set encoded in the empty array without
>> explicitly introducing code for this size of array. From a
>> programatically viewpoint, this seems quite odd.
>
> FWIW, as of 8.2 the best option will probably be to use
> "col = ANY (array)", which does support zero-length arrays
> if you use either an out-of-line parameter or an array literal.
That looks nice.. is ANY in the SQL-spec?
Jesper
--
Jesper Krogh, jesper@krogh.cc
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To: pgsql-sql@postgresql.org
Cc: jesper@krogh.cc, tgl@sss.pgh.pa.us, postgresql@aranya.com
Subject: Re: The empty list?
In-Reply-To: <454AE5B5.4050106@krogh.cc>
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