[Featureserver] Featureserver caching

[david creane]

>>crschmidt=# create table osi.roads (id int);
>>ERROR:  schema "osi" does not exist

>>I don't know how I'd create a table like that. Do you have an 'osi'
>>schema or something?

Yes, sry, it is a schema, forget what i had said, im only figuring out 
postgres as i go along, using a database set up by someone else. I set the 
search_path to include osi. 

Just a few questions.
When calling a wms layer say at zoom level 1 , tilecache make 6 calls to 
server say for example passing different  sets of numbers ranging from the 
bounding box of 4885,-62828,381091,501480

http://localhost/~dave/tilecache/tilecache.cgi?LAYERS=ireland_coast_permanent&FORMAT=image%2Fpng&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=EPSG%3A29900&BBOX=192988,-62828,381091,125275&WIDTH=256&HEIGHT=256
............ 
http://localhost/~dave/tilecache/tilecache.cgi?LAYERS=ireland_coast_permanent&FORMAT=image%2Fpng&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=EPSG%3A29900&BBOX=4885,313378,192988,501481&WIDTH=256&HEIGHT=256

but when feature server makes its call to the database for example 
http://localhost/~dave/featureserver/featureserver.cgi/hospital?format=WFS&maxfeatures=1000&SERVICE=WFS&VERSION=1.0.0&REQUEST=GetFeature&SRS=EPSG%3A29900&BBOX=-100922.9375,-184801.5390625,486898.9375,623453.5390625
-100922.9375,-184801.5390625,486898.9375,623453.5390625
it is using a bigger bounding box. 

for example if i request the map from my wms server using the bounding box of 
4885,-62828,381091,501480 like so 
http://localhost:8090/hai2/workspaces/siteworks/exploremaps/default/query/ddddddddddd475/@@wms?LAYERS=&REPROJECT=false&NUMZOOMLEVELS=12&FORMAT=image%2Fpng%3Bmode%3DRGBA&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=EPSG%3A29900&BBOX=4885,-62828,381091,501480&WIDTH=600&HEIGHT=900
i get my close up map of ireland
the -100922.9375,-184801.5390625,486898.9375,623453.5390625 one returns a 
zoomed out version of it
http://localhost:8090/hai2/workspaces/siteworks/exploremaps/default/query/ddddddddddd475/@@wms?LAYERS=&REPROJECT=false&NUMZOOMLEVELS=12&FORMAT=image%2Fpng%3Bmode%3DRGBA&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=EPSG%3A29900&BBOX=-100922.9375,-184801.5390625,486898.9375,623453.5390625&WIDTH=600&HEIGHT=900

why is the feature server using a greater bounding box then the one i define 
in the layer options. I know the tilebounds is calculated in 
openlayers/lib/OpenLayers/Layer/WFS.js but im not sure as to why it is done 
like this.