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

Re: BUG #6483: Rows being evaluated, although being outside the LIMIT / OFFSET boundaries

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Marti Raudsepp <marti(at)juffo(dot)org>
Cc: kouber(at)saparev(dot)com, pgsql-bugs(at)postgresql(dot)org
Subject: Re: BUG #6483: Rows being evaluated, although being outside the LIMIT / OFFSET boundaries
Date: 2012-02-22 21:40:32
Message-ID: 25657.1329946832@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-bugs
Marti Raudsepp <marti(at)juffo(dot)org> writes:
> According to this model, evaluating SELECT clause fields for *all*
> found rows is done in step 5, whereas LIMIT/OFFSET are only applied
> later at step 9. So we're already bending the rules here (in general
> we don't do such optimizations around volatile functions). The worst
> thing is that it's inconsistent -- the LIMIT gets applied when
> computing the SELECT list, but OFFSET doesn't.

On what grounds do you say that?  LIMIT and OFFSET are practically the
same thing internally, and are certainly applied in the same way.

			regards, tom lane

In response to

Responses

pgsql-bugs by date

Next:From: Marti RaudseppDate: 2012-02-22 22:05:22
Subject: Re: BUG #6483: Rows being evaluated, although being outside the LIMIT / OFFSET boundaries
Previous:From: Marti RaudseppDate: 2012-02-22 21:13:03
Subject: Re: BUG #6483: Rows being evaluated, although being outside the LIMIT / OFFSET boundaries

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