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Date: Fri, 23 Mar 2018 12:45:34 -0300
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Konstantin Knizhnik <k.knizhnik@postgrespro.ru>
Cc: Stephen Frost <sfrost@snowman.net>,
	Michael Paquier <michael.paquier@gmail.com>,
	Simon Riggs <simon@2ndquadrant.com>,
	Christoph Berg <myon@debian.org>,
	Thomas Munro <thomas.munro@enterprisedb.com>,
	Peter Eisentraut <peter.eisentraut@2ndquadrant.com>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] Surjective functional indexes
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Konstantin Knizhnik wrote:

> rd_projidx is not a list, it is Bitmapset. It is just one of many bitmap
> sets in RelationData:

Yes, but the other bitmapsets are of AttrNumber of the involved column.
They new one is of list_nth() counters for items in the index list.
That seems weird and it scares me -- do we use that coding pattern
elsewhere?  Maybe use an array of OIDs instead?

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services