Skip site navigation (1) Skip section navigation (2)

Re: Boolean error

From: Greg Stark <gsstark(at)mit(dot)edu>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: Boolean error
Date: 2004-11-29 06:18:05
Message-ID: 874qj9uqjm.fsf@stark.xeocode.com (view raw or flat)
Thread:
Lists: pgsql-general
Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

> There was some talk awhile ago of preventing flattening when the
> subquery targetlist contains volatile functions, but we didn't
> have any consensus that the cure would be better than the disease.
> (In particular, since user-defined functions default to being
> considered volatile, such a restriction could easily cripple
> optimization of subqueries.)

Thinking aloud... Postgres could have a VOLATILE function attribute to
explicitly mark functions requiring special care.

The default could be sort of a best-guess
usually-volatile-but-sometimes-takes-liberties-when-convenient compromise.
Perhaps eventually warning on functions created without being explicitly
VOLATILE/STABLE/IMMUTABLE.

Well, I guess Postgres can't warn on a valid SQL function if it's interested
in spec conformance. But it could be an option to do so.

-- 
greg


In response to

pgsql-general by date

Next:From: Michael FuhrDate: 2004-11-29 06:43:28
Subject: Re: How many views...
Previous:From: Shachar ShemeshDate: 2004-11-29 04:41:09
Subject: Re: sequencing two tables

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group