Message-ID: <4C7BBAA1.6040808@2ndquadrant.com>
Date: Mon, 30 Aug 2010 10:05:21 -0400
From: Greg Smith <greg@2ndquadrant.com>
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To: Eliot Gable <egable+pgsql-performance@gmail.com>
CC: pgsql-performance@postgresql.org
Subject: Re: GPU Accelerated Sorting
References: <AANLkTimjYxrvMGMLhh3q=82iNiKKjQvPRcrsgX7DHcMp@mail.gmail.com>
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Eliot Gable wrote:
> Not sure if anyone else saw this, but it struck me as an interesting
> idea if it could be added to PostgreSQL. GPU accelerated database
> operations could be very... interesting. Of course, this could be
> difficult to do in a way that usefully increases performance of
> PostgreSQL, but I'll leave that up to you guys to figure out.
>   

This comes up every year or so.  The ability of GPU offloading to help 
with sorting has to overcome the additional latency that comes from 
copying everything over to it and then getting all the results back.  If 
you look at the typical types of sorting people see in PostgreSQL, it's 
hard to find ones that are a) big enough to benefit from being offloaded 
to the GPU like that, while also being b) not so bottlenecked on disk 
I/O that speeding up the CPU part matters.  And if you need to sort 
something in that category, you probably just put an index on it instead 
and call it a day.

If you made me make a list of things I'd think would be worthwhile to 
spend effort improving in PostgreSQL, this would be on the research 
list, but unlikely to even make my personal top 100 things that are work 
fiddling with.

-- 
Greg Smith  2ndQuadrant US  Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com   www.2ndQuadrant.us