Re: [pgsql-performance] function difference(geometry, geometry) is SLOW!

>
> Date: Mon, 16 Jun 2008 11:06:44 +0200 (CEST)
> From: "luke(dot)78(at)libero(dot)it" <luke(dot)78(at)libero(dot)it>
> To: pgsql-performance(at)postgresql(dot)org
> Subject: function difference(geometry,geometry) is SLOW!
> Message-ID:
> <10574478(dot)390451213607204584(dot)JavaMail(dot)defaultUser(at)defaultHost>
>
> Hi,
> In my pgsql procedure, i use the function
>
> geometryDiff := difference
> (geometry1,geometry2);
>
> but this function is very slow!!!
> What can I do to
> speed this function?
> Exists a special index for it?
>
> Thanks in advance!
> Luke

Hi,

this is a postgis function. Postgis is an independent project
and you might want to ask there:

http://www.postgis.org/mailman/listinfo/postgis-users

or

http://www.faunalia.com/cgi-bin/mailman/listinfo/gfoss
(italian).

Anyway, as long as you just compute the difference between
2 given shapes, no index can help you. Indices speed up
searches...

Bye,
Chris.