From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: Floris Van Nee <florisvannee@optiver.com>
Cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: jesper.pedersen@redhat.com <jesper.pedersen@redhat.com>
Cc: David Rowley <david.rowley@2ndquadrant.com>
Cc: Thomas Munro <thomas.munro@gmail.com>
Cc: James Coleman <jtc331@gmail.com>
Cc: Rafia Sabih <rafia.pghackers@gmail.com>
Cc: Jeff Janes <jeff.janes@gmail.com>
Cc: Peter Geoghegan <pg@bowt.ie>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: Thomas Munro <thomas.munro@enterprisedb.com>
Cc: Bhushan Uparkar <bhushan.uparkar@gmail.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Cc: Alexander Korotkov <a.korotkov@postgrespro.ru>
Subject: Re: Index Skip Scan
Date: Sun, 22 Sep 2019 23:02:04 -0300
Message-ID: <20190923020204.GA2781@alvherre.pgsql> (raw)
In-Reply-To: <CA+q6zcV2Ti99RSOHsauppY2_JZ8zvWhUmN9NWo0R4xf6HL=Szg@mail.gmail.com>
On 2019-Sep-22, Dmitry Dolgov wrote:
> > I think multiplying two ScanDirections to watch for a negative result is
> > pretty ugly:
>
> Probably, but the only alternative I see to check if directions are opposite is
> to check that directions come in pairs (back, forth), (forth, back). Is there
> an easier way?
Maybe use the ^ operator?
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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To: pgsql-hackers@postgresql.org
Cc: alvherre@2ndquadrant.com, 9erthalion6@gmail.com, florisvannee@optiver.com, horikyota.ntt@gmail.com, jesper.pedersen@redhat.com, david.rowley@2ndquadrant.com, thomas.munro@gmail.com, jtc331@gmail.com, rafia.pghackers@gmail.com, jeff.janes@gmail.com, pg@bowt.ie, tomas.vondra@2ndquadrant.com, thomas.munro@enterprisedb.com, bhushan.uparkar@gmail.com, a.korotkov@postgrespro.ru
Subject: Re: Index Skip Scan
In-Reply-To: <20190923020204.GA2781@alvherre.pgsql>
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