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Re: COUNT(*) and index-only scans - Mailing list pgsql-hackers

From Greg Stark
Subject Re: COUNT(*) and index-only scans
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Msg-id CAM-w4HOBfxNcexc+gyhUe4LSYLeSsnPrtZsn3KcTaeK8h7Tq2A@mail.gmail.com
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In response to COUNT(*) and index-only scans  (Bruce Momjian <bruce@momjian.us>)
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On Mon, Oct 10, 2011 at 6:23 PM, Bruce Momjian <bruce@momjian.us> wrote:
> I talked to Robert Haas and he said that index-only scans do not
> optimize COUNT(*).  Is this something we can do for PG 9.2?  Is anyone
> working on this?

People usually conflate multiple problems when they talk about
"count(*). The usual case people are concerned about would require
materialized views, not index-only scans.


--
greg

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