From: | Teodor Sigaev <teodor(at)sigaev(dot)ru> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | Pgsql Hackers <pgsql-hackers(at)postgresql(dot)org>, Martin Schäfer <Martin(dot)Schaefer(at)cadcorp(dot)com> |
Subject: | Re: Incorrect cursor behaviour with gist index |
Date: | 2008-10-17 20:41:58 |
Message-ID: | 48F8F896.8030409@sigaev.ru |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
> Seems like a lotta work for a partial solution :-(. Probably the path
> of least resistance is to teach the planner that only some index AMs can
> do backwards scan. That would result in a Materialize buffer getting
> placed in front of the query if the user demanded scroll capability,
> but it would cost nothing in the more typical case where backwards scan
> isn't needed.
Probably, it will be a better solution. In this case GiST code could be
simplified - remove support of backward scan (in any case not fully workable)
>
> It should be sufficient to specify this in pg_am, right? Or could the
> opclass or indexkey details affect it?
I don't see any examples where it depends on opclass or index key, that's is a
AM property.
>
> BTW, can GIN do backwards scan?
No, at all.
--
Teodor Sigaev E-mail: teodor(at)sigaev(dot)ru
WWW: http://www.sigaev.ru/
From | Date | Subject | |
---|---|---|---|
Next Message | Simon Riggs | 2008-10-17 20:44:25 | Re: Hot Standby: First integrated patch |
Previous Message | Greg Stark | 2008-10-17 20:41:52 | Re: Block-level CRC checks |