Re: No heap lookups on index

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: "Jim C. Nasby" <jnasby@pervasive.com>
Cc: Jeremy Drake <pgsql@jdrake.com>, David Scott <davids@apptechsys.com>, pgsql-hackers@postgresql.org
Date: 2006-01-19T23:20:07Z
Lists: pgsql-hackers, pgsql-general
"Jim C. Nasby" <jnasby@pervasive.com> writes:
> Basically, numbers talk. If there were convincing numbers for something
> that wasn't a corner-case that showed a marked improvement then there'd
> be much more interest in getting this into the backend in some fashion.

I've got no doubt that there are *some* "non corner" cases for which
this would be a win.  The lower the update load on the database, the
better it's going to look.  The issue really is where does it start
being a loss, and can you convince us that those cases are all "corner"
ones?

(The subtext here, of course, is the assumption that it's an
all-or-nothing choice.  I'm of the opinion that supporting both options
would be infeasible from a code complexity and maintenance standpoint;
but a simple patch that did both would of course prove that opinion
wrong ...)

			regards, tom lane