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From: Tom Lane <[email protected]>
To: Claudio Freire <[email protected]>
Cc: Justin Pryzby <[email protected]>
Cc: postgres performance list <[email protected]>
Subject: Re: index fragmentation on insert-only table with non-unique column
Date: Sun, 05 Jun 2016 12:03:58 -0400
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Claudio Freire <[email protected]> writes:
> So correlated index scans look extra favourable vs bitmap index scans
> because bitmap heap scans consider random page costs sans correlation
> effects (even though correlation applies to bitmap heap scans as
> well).

Really?  How?  The index ordering has nothing to do with the order in
which heap tuples will be visited.

			regards, tom lane


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