Date: Wed, 4 Sep 2019 16:45:38 -0400
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: Floris Van Nee <florisvannee@optiver.com>,
	Kyotaro Horiguchi <horikyota.ntt@gmail.com>,
	"jesper.pedersen@redhat.com" <jesper.pedersen@redhat.com>,
	David Rowley <david.rowley@2ndquadrant.com>,
	Thomas Munro <thomas.munro@gmail.com>,
	James Coleman <jtc331@gmail.com>,
	Rafia Sabih <rafia.pghackers@gmail.com>,
	Jeff Janes <jeff.janes@gmail.com>, Peter Geoghegan <pg@bowt.ie>,
	Tomas Vondra <tomas.vondra@2ndquadrant.com>,
	Thomas Munro <thomas.munro@enterprisedb.com>,
	Bhushan Uparkar <bhushan.uparkar@gmail.com>,
	PostgreSQL-development <pgsql-hackers@postgresql.org>,
	Alexander Korotkov <a.korotkov@postgrespro.ru>
Subject: Re: Index Skip Scan
Message-ID: <20190904204538.GA14030@alvherre.pgsql>
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Surely it isn't right to add members prefixed with "ioss_" to
struct IndexScanState.

I'm surprised about this "FirstTupleEmitted" business.  Wouldn't it make
more sense to implement index_skip() to return the first tuple if the
scan is just starting?  (I know little about executor, apologies if this
is a stupid question.)

It would be good to get more knowledgeable people to review this patch.
It's clearly something we want, yet it's been there for a very long
time.

Thanks

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