From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Greg Stark <stark(at)mit(dot)edu> |
Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: index-only scans |
Date: | 2011-10-09 21:54:11 |
Message-ID: | 26032.1318197251@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Greg Stark <stark(at)mit(dot)edu> writes:
> On Sun, Oct 9, 2011 at 9:03 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> At the moment I'm leaning to approach #3, but I wonder if anyone has
>> a different opinion or another idea altogether.
> Would any of these make it more realistic to talk about the crazy
> plans Heikki suggested like doing two index scans, doing the join
> between the index tuples, and only then looking up the visibility
> information and remaining columns for the tuple on the matching rows?
I don't think it's particularly relevant --- we would not want to use
weird representations of the Vars outside the index scan nodes. Above
the scan they'd be just like any other upper-level Vars.
(FWIW, that idea isn't crazy; I remember having discussions of it back
in 2003 or so.)
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Greg Stark | 2011-10-09 22:23:07 | Re: index-only scans |
Previous Message | Greg Stark | 2011-10-09 21:31:42 | Re: index-only scans |