[Mapserver-users] classification performance

[bartvde at xs4all.nl]

Hi list,

I have been doing some performance tests this morning on a shapefile and a
tiled version of the same shapefile. The most astonishing outcome for me
was however the amount of time a classifcation takes. I have a pretty
complex classification for my dataset with 28 classes, mostly using
regular expressions.

Here are the results of the test (Intel Xeon 2,4 Ghz, 1,5 Gb memory,
Windows 2000 Server), tests performed with Microsoft Web Application
Stress Tool on the same server, during 1 minute of continuous requests:

1 Shapefile (1,6 Gb) "without" classification (1 class): 1.4 sec
Tiled shapefiles in 10x10 (=100) tiles without classification: 0.7 sec
1 Shapefile (1,6 Gb) with classification: 2.4 sec
Tiled shapefiles in 10x10 (=100) tiles with classification: 1.9 sec

So executing the classification on the dataset costs approximately 1-1.2
seconds, which is a more than reading the data in the case of a tiled
dataset. *** Is this to be expected? ***

bbox used: 160000,445000,170000,455000 (10.000 x 10.000 m)
image dimensions: 750x750 pixels
WMS protocol

Best regards,
Bart