Re: index-only scans vs. Hot Standby, round two - Mailing list pgsql-hackers

From Tom Lane
Subject Re: index-only scans vs. Hot Standby, round two
Date
Msg-id 24054.1334585976@sss.pgh.pa.us
Whole thread Raw
In response to Re: index-only scans vs. Hot Standby, round two  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
Responses Re: index-only scans vs. Hot Standby, round two  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> Can we have a "soft" hot standby conflict that doesn't kill the query, 
> but disables index-only-scans?

Well, there wouldn't be any way for the planner to know whether an
index-only scan would be safe or not.  I think this would have to look
like a run-time fallback.  Could it be structured as "return that the
page's all-visible bit is not set, instead of failing?"  Or am I
confused about where the conflict is coming from?
        regards, tom lane


pgsql-hackers by date:

Previous
From: Andrew Dunstan
Date:
Subject: Re: JSON for PG 9.2
Next
From: Merlin Moncure
Date:
Subject: Re: JSON for PG 9.2