[postgis-devel] Caching function calls with CTEs

[Paragon Corporation]

Windowing functions come in especially handy for nearest neighbor search
getting top n per location.  We are going to demonstrate that in our OSCON
conference.  Slides and materials will of course will be available after the
conference is over.

  _____  

From: postgis-devel-bounces at postgis.refractions.net
[mailto:postgis-devel-bounces at postgis.refractions.net] On Behalf Of
nicklas.aven at jordogskog.no
Sent: Sunday, July 19, 2009 1:52 PM
To: PostGIS Development Discussion
Subject: Re: [postgis-devel] Caching function calls with CTEs


This is really cool Regina and Leo

It's a new way of thinking for me to to use this recursive thing, but I can
see that it is very useful.
I hope I will get some time in the near future to try to understand it
better.

Also the windowing functions together with postgis aggregate function will
be fun to try.

/Nicklas





2009-07-17 Paragon Corporation wrote:

Nicklas,
>
>We tried CTEs against that annoying issue of functions not being cached in
>the same row. Preliminary tests seem to suggest it might be the ideal
>solution for this.
>We suspect it will also be good in many other scenarios where the planner
>refuses to use indexes in the right order etc.
>
>http://www.postgresonline.com/journal/index.php?/archives/127-guid.html
>
>We are going to test with real spatial queries next in preparation for our
>OSCON presentation next week.
>
>http://en.oreilly.com/oscon2009/public/schedule/detail/7859
>Sadly it looks like we probably won't have 1.4 out in time for our
>presentation - oh well :(
>
>
>Anyrate take a look and test with your data to see if it speeds up your
>queries.
>
>L & R
>
>
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>
> 
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