Performance improvement

[Antonio Iandolo]

Hi all,
I've set up MapServer with a 4 layers map on an Oracle10g database thru
a native connection (not OGR).

The largest layer (which takes about 40% of the total time) is a polygon
type of about 60,000 records (with a spatial index on the geom column)
which isn't involved in any queryBy* php_mapscript function (only
$map->setExtent) and has this DATA definition:
  DATA "GEOM FROM MYLAYER USING SRID 8307 NONE"


The whole page takes about 9-11 seconds to be rendered, while the same
php script (exactly the same, except for the mapfile), when interfacing
ESRI shapefiles, (Oracle data come from ESRI thru shp2sdo.exe utility)
takes less than 4 seconds in total...

The most of time (about 80-90%) is taken by the $map->draw() method,
where I supose it applies the spatial filter to determine which shapes
are to be rendered...

How could I improve these performance? Any suggestion/hint to check any
bottleneck?

My environment is:
- Pentium 4 - 1.8GHz - 512MB RAM
- Windows XP Professional SP1
- Apache 2.0.55
- MapServer 4.8.3 
- php 4.4.3-dev (MS4W 1.5.3)
- php_mapscript_48.dll
- Oracle10g (XE) 

Thanks in advance,
Antonio