Re: Improving executor performance

On Fri, Jun 24, 2016 at 05:25:27PM -0700, Peter Geoghegan wrote:
> On Fri, Jun 24, 2016 at 4:29 PM, Andres Freund <andres@anarazel.de> wrote:
> > As a motivation, here's a somewhat juicy example of the benefits that
> > can be gained (disabled parallelism, results vary too much):
> > SELECT l_linestatus, SUM(l_quantity) FROM lineitem GROUP BY 1 ORDER BY 2 DESC LIMIT 10 ;
> > non-optimized: 9075.835 ms
> >     optimized: 5194.024 ms
> >
> > and that's far from doing all the possible work for that query;
> > especially the batching is far from optimal.
> 
> That's pretty great. Let me first just say that I think that your
> broadly have the right idea here, and that it will likely be a big
> area to work on in the years ahead. This may become a big, general
> area with many sub-projects, kind of like parallelism. Also, I think
> it's very much complementary to parallelism.

Agreed.  I did put out a blog entry about this in April that has links
to some external projects trying to address this issue:
http://momjian.us/main/blogs/pgblog/2016.html#April_1_2016

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com

+ As you are, so once was I. As I am, so you will be. +
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