MapServer/PostGIS query mechanism should use primary key on a table

[margottid@…]

After installing PostGIS and importing data from Shapefile, I noticed that CGI 
query/nquery were from 10 to 15 times slower than if I were using shapefiles.

I tried to add many and many indexes on my fields, but solution came from Paul 
Ramsey: adding an oid index.

He also suggested to issue this bug, saying that "the mapserver/postgis query 
mechanism should be upgraded to automatically use the primary key on a table 
if such a key exists."

Daniele

[mark@…]

MapServer will now attempt to determine if a single primary key is set on a
table, if no "using unique" clause is found.  The OID is only used if no unique
clause is provided, AND no primary key (or a multi-column primary key) is found.