Re: Preventing index scans for non-recoverable index AMs

From: Simon Riggs <simon(at)2ndQuadrant(dot)com>
To: pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Preventing index scans for non-recoverable index AMs
Date: 2008-12-18 02:23:10
Message-ID: 1229566990.4793.276.camel@ebony.2ndQuadrant
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On Wed, 2008-12-17 at 21:26 +0000, Simon Riggs wrote:
> Hot Standby won't work with hash indexes because they are
> non-recoverable.
>
> We have a number of ways of dealing with this:

> 2. Specific Solution: make hashcostestimate() massively increase cost of
> scans during recovery so that they will very seldom be picked and make
> hashbeginscan() refuse scans during recovery in case they do happen

> (2) seems most appropriate, since it will last only until (1) is
> complete in a later release.

Code *fragment* enclosed here for discussion. (Not an independent patch)

--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support

Attachment Content-Type Size
hs.hashindex.v6.patch text/x-patch 2.5 KB

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