[postgis-users] strange benchmark results

[Andreas Brandl]

Hi Mark, folks,

----- "Mark Cave-Ayland" <mark.cave-ayland at siriusit.co.uk> wrote:
> Andreas Brandl wrote:
> 
> >> As a quick test, I would suggest upgrading to the new Windows
> >> StackBuilder packages since they contain GEOS 3.2.0 which had a
> number
> >> of memory leaks fixed and see if you see the same behaviour on Test
> 1,
> >> i.e. slowly increasing query times.
> > 
> > This one is in the 'queue'.
> 
> Okay, great. Let us know how you get on.

There are now results for PostGIS 1.4.1 with GEOS 3.2.0 on Windows XP. The effect does also show up here and also affects some other queries (labeled Equals and Union) which were not affected before (on PostGIS 1.4.0 on different platforms). 

The whole report on this topic may be retrieved at [1,2]. Newly affected cases go to the bottom of the table. The new result on postgis 1.4.1 is on the left side.

Mark, is it worth filing a bug on this topic? Is there anything else I may provide?

> In other words, I believe that due to differences in the filesystem
> and  OS architecture that the performance will never be equal. However I am
> surprised by the inconsistency of queries on the Windows side. Was
> your test box a Windows server or workstation edition? And did you attempt
> to optimise it for server rather than workstation use?

The test box was a Win XP Professional which I tried to 'optimise' by disabling all unnecessary services und processes. The OS included all patches but no other software installations (and no antivirus and the like). However, I agree that a workstation edition is not the best OS to run server software at. 

Anyway, I may be able to run the tests on a Windows server edition. In case this is interesting for you, please drop me a line. 

Mark, thanks for the insight!

Regards,
Andreas

[1] http://students.fim.uni-passau.de/~brandlan/postgis/ml/postgiseffects.html 
[2] http://students.fim.uni-passau.de/~brandlan/postgis/ml/postgiseffects_big.html