Re: Another try at reducing repeated detoast work for PostGIS - Mailing list pgsql-hackers

From Jeff Davis
Subject Re: Another try at reducing repeated detoast work for PostGIS
Date
Msg-id 1250533758.16514.12.camel@monkey-cat.sm.truviso.com
Whole thread Raw
In response to Another try at reducing repeated detoast work for PostGIS  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Another try at reducing repeated detoast work for PostGIS  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Mon, 2009-08-17 at 13:37 -0400, Tom Lane wrote:
> Thinking about it again, it seems to me that a much narrower patch
> could solve the specific forms of the problem that the PostGIS folk
> are seeing.  Instead of trying to have a general-purpose method of
> preventing repeat de-toasting, we could just prevent it for inner
> indexscans by having ExecIndexEvalRuntimeKeys() detoast anything it's
> passing to the index AM. 

With this patch, are there still situations where we should be concerned
about repeated de-toasting, or does this solve the biggest part of the
problem?

If so, is it possible that two similar plans for the same query might
perform differently due to repeated de-toasting?

Regards,Jeff Davis



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