From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: Melanie Plageman <melanieplageman@gmail.com>
Cc: Hubert Zhang <hzhang@pivotal.io>
Cc: hackers <pgsql-hackers@postgresql.org>
Cc: Thomas Munro <thomas.munro@gmail.com>
Subject: Re: accounting for memory used for BufFile during hash joins
Date: Tue, 3 Sep 2019 12:36:33 -0400
Message-ID: <20190903163633.GA16230@alvherre.pgsql> (raw)
In-Reply-To: <20190711154011.lmkp7jyd3e2zfcnx@development>
On 2019-Jul-11, Tomas Vondra wrote:
> On Wed, Jul 10, 2019 at 04:51:02PM -0700, Melanie Plageman wrote:
> > I think implementing support for parallel hashjoin or explicitly
> > disabling it would be the bare minimum for this patch, which is why I
> > made 2 its own item. I've marked it as returned to author for this
> > reason.
>
> OK. I'm a bit confused / unsure what exactly our solution to the various
> hashjoin issues is. I have not been paying attention to all the various
> threads, but I thought we kinda pivoted to the BNL approach, no? I'm not
> against pushing this patch (the slicing one) forward and then maybe add
> BNL on top.
So what's a good way forward for this patch? Stalling forever like a
glacier is not an option; it'll probably end up melting. There's a lot
of discussion on this thread which I haven't read, and it's not
immediately clear to me whether this patch should just be thrown away in
favor of something completely different, or it can be considered a first
step in a long road.
--
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, tomas.vondra@2ndquadrant.com, melanieplageman@gmail.com, hzhang@pivotal.io, thomas.munro@gmail.com
Subject: Re: accounting for memory used for BufFile during hash joins
In-Reply-To: <20190903163633.GA16230@alvherre.pgsql>
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