[mapserver-users] MapServer 5.2.1 performance

[Daniel Morissette]

Gorka Lopez wrote:
> 
> * 18 millisecods per non-visible layer (layers that are not visible in the
> map' scale (80 layers))
> 
> Is there any solution to improve this results (I just use tilechache
> metatile property)? I think that 18 milliseconds per non-visible layer is
> too much (only for evaluating wether the requested tile is contained in the
> layer's min/max scale)
> 

Do you use MINSCALEDENOM/MAXSCALEDENOM in your layer definition in the 
mapserver mapfile? If yes then the time should be zero (or < 1 msec) for 
layers that are out of scale.

Or did you instead mean that it takes 18msecs to process layers whose 
data is outside of the requested tile extents? That could be explained 
by the fact that I think the postgis driver does not know the data 
extents until it queries the database and has no way to tell that a 
layer has no visible features for a given extent until it runs the query 
on the database.

A way to force MapServer to skip those layers would be to set EXTENT in 
each layer to a valid value (the data extents for each layer). Then if a 
given layer's EXTENT value does not overlap the extents of the requested 
tile it should be skipped right away. Note that I didn't test this just 
now, but this is my understanding of the way the postgis driver works in 
MapServer.

Daniel
-- 
Daniel Morissette
http://www.mapgears.com/