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Re: FDW handling count(*) through AnalyzeForeignTable or other constant time push-down - Mailing list pgsql-hackers

From Tom Lane
Subject Re: FDW handling count(*) through AnalyzeForeignTable or other constant time push-down
Date
Msg-id 13359.1456467682@sss.pgh.pa.us
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In response to FDW handling count(*) through AnalyzeForeignTable or other constant time push-down  ("Gabe F. Rudy" <rudy@goldenhelix.com>)
Responses Re: FDW handling count(*) through AnalyzeForeignTable or other constant time push-down
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"Gabe F. Rudy" <rudy@goldenhelix.com> writes:
> Is there any way to convince Postgres FDW to leverage the analyze row counts or even the "double* totalRowCount"
returnedfrom the AcquireSampleRows callback from my AnalyzeForeignTable function so that it does not do a full-table
scanfor a COUNT(*) etc?
 

No.  In PG's view, ANALYZE-based row counts are imprecise by definition.
        regards, tom lane

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