From: Tom Lane <tgl@sss.pgh.pa.us>
To: Markus Schaber <schabi@logix-tt.com>
Cc: PostgreSQL SQL List <pgsql-sql@postgresql.org>
Subject: Re: Set generating functions and subqueries
Date: Mon, 13 Mar 2006 09:57:39 -0500
Message-ID: <7169.1142261859@sss.pgh.pa.us> (raw)
In-Reply-To: <441566CF.2040105@logix-tt.com>
References: <44116ED2.9060901@logix-tt.com>
<5142.1142002128@sss.pgh.pa.us>
<441566CF.2040105@logix-tt.com>
Markus Schaber <schabi@logix-tt.com> writes:
> Tom Lane wrote:
>> The fact that the other form is even allowed is more of a holdover from
>> PostQUEL than something we have consciously decided is a good idea.
>> (IMHO it's actually a fairly *bad* idea, because it does not work nicely
>> when there's more than one SRF in the same targetlist.) It'll probably
>> get phased out someday, if we can find a way to replace the
>> functionality. I seem to recall speculating that SQL2003's LATERAL
>> tables might do the job.
> AFAICS, it can be replaced with JOINs:
Not really; the case where joins don't help is where you want to
generate the SRF's output for each of the values appearing in a table.
There's an example in "SQL Functions Returning Sets" in the manual:
http://www.postgresql.org/docs/8.1/static/xfunc-sql.html#AEN31646
regards, tom lane
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To: pgsql-sql@postgresql.org
Cc: tgl@sss.pgh.pa.us, schabi@logix-tt.com
Subject: Re: Set generating functions and subqueries
In-Reply-To: <7169.1142261859@sss.pgh.pa.us>
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