Re: Avoiding hash join batch explosions with extreme skew and weird stats

From: Peter Geoghegan <pg(at)bowt(dot)ie>
To: Melanie Plageman <melanieplageman(at)gmail(dot)com>
Cc: Robert Haas <robertmhaas(at)gmail(dot)com>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, Thomas Munro <thomas(dot)munro(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Avoiding hash join batch explosions with extreme skew and weird stats
Date: 2019-07-31 03:11:47
Message-ID: CAH2-Wz=JPP02V-CxUvDqVkN=wWtvGfoHDTrU5x5Jsbujk-b6oA@mail.gmail.com
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On Tue, Jul 30, 2019 at 8:07 PM Melanie Plageman
<melanieplageman(at)gmail(dot)com> wrote:
> For the actual write to disk, I'm pretty sure I get that for free from
> the BufFile API, no?
> I was more thinking about optimizing when I call BufFileWrite at all.

Right. Clearly several existing buffile.c users regularly have very
small BufFileWrite() size arguments. tuplestore.c, for one.

--
Peter Geoghegan

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