From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Vivek Khera <khera(at)kcilink(dot)com> |
Cc: | PGSQL Mailing List <pgsql-general(at)postgresql(dot)org> |
Subject: | Re: partitioned table query question |
Date: | 2007-12-11 17:45:44 |
Message-ID: | 19982.1197395144@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general pgsql-hackers |
Vivek Khera <khera(at)kcilink(dot)com> writes:
> I, along with at least Erik, was thinking that the constraint
> expression would be evaluated to determine whether to include the
> partition in the final plan. Based on Tom's description, it is not
> the case: the planner basically proves that the constraint will be
> false. Until this was clarified, Tom's points totally confused the
> heck out of me.
> It would be amazingly wonderful if this distinction could be posted to
> the online docs. It will surely help future generations :-)
Feel free to send in a proposed doc patch. I'm not very clear on where
you think this should go or what it should say instead of what it does
say.
BTW, I always think of it the other way around: we're proving that the
WHERE condition must be false for any row meeting the check constraint.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Steve Atkins | 2007-12-11 17:46:24 | Re: Hijack! |
Previous Message | Bill Moran | 2007-12-11 17:41:47 | Re: Hijack! |
From | Date | Subject | |
---|---|---|---|
Next Message | Peter Eisentraut | 2007-12-11 18:03:03 | Re: archive_command failures report confusing exit status |
Previous Message | Vivek Khera | 2007-12-11 17:24:12 | Re: partitioned table query question |