Re: bitmap scans, btree scans, and tid order

From: Neil Conway <neilc(at)samurai(dot)com>
To: Jeffrey Baker <jwbaker(at)acm(dot)org>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: bitmap scans, btree scans, and tid order
Date: 2005-05-16 06:35:32
Message-ID: 42883F34.9050809@samurai.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Jeffrey Baker wrote:
> Would you take a patch that retained the optimized executions of plans
> returning 1 tuple and also fixed the random heap problem?

Can you elaborate on what you're proposing? Obviously sorted b+-tree
output is important for a lot more than just min()/max(). I don't see an
obvious way to produce sorted output from a bitmap tree index scan
without requiring an additional sort step (which would be rather
pointless -- the whole point of the optimization is to avoid an
additional sort).

-Neil

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Jeffrey Baker 2005-05-16 06:58:13 Re: bitmap scans, btree scans, and tid order
Previous Message Jeffrey Baker 2005-05-16 06:14:51 Re: bitmap scans, btree scans, and tid order