[postgis-users] mechanix of a query

[P Kishor]

I am trying to understand the mechanics of a getfeatureinfo query. My
setup is data in Pg/PostGIS, served by MapServer via WMS, with
OpenLayers in the front. When I click on a map and send a
GetFeatureInfo query, MapServer grabs the x,y sent in the URL, and,
for the layer (also sent in the URL), finds the row in the table which
contains the x,y of my click.

How does MapServer do that?

Does it run a Pg/PostGIS query for this?
How can I find out the syntax of this query?

If a GetFeatureInfo takes too long, what can I do to speed it up?


-- 
Puneet Kishor