Kristian,
My understanding is that shapefiles with a spatial index (qix, generated
with the shptree utility in mapserver) are actually faster than postgis
access to the same data. I've had excellent performance with shapefiles
for the display side of things, and PostGIS for the querying capabilities.
Percy
Thy, Kristian wrote:
Quoting the Raster Data Access HOWTO
<http://mapserver.gis.umn.edu/docs/howto/raster_data>:
"The list of files forming a layer can be stored in a shapefile with
polygons
representing the footprint of each file, and the name of the files.
This is
called a TILEINDEX ..."
The tileindex, we're told, is defined in the map file like this:
LAYER
NAME "hpool"
STATUS ON
TILEINDEX "hp2.shp"
TILEITEM "Location"
TYPE RASTER
END
My question is then: Is it possible (and if yes, desirable) to read the
tileindex from a PostGIS data source instead of a shapefile - i.e. use
gdatindex to create the tileindex, then convert the index .shp using
shp2pgsql and stuff it into PostGIS. My understanding is that using
plain ole shapefiles you miss out on the gist indexing and thus suffer
a performance loss.
best regards,
Kristian Thy
--
David Percy
Geospatial Data Manager
Geology Department
Portland State University
http://gisgeek.pdx.edu
503-725-3373
