[postgis-users] alpha GT2 Web Map Server with PostGIS support

[David Blasby]

Some time in the future, you will be allowing people to get their data from arbitrary
SQL statements or from user defined views.

Unfortunately, OID is usually not present in these datasources.  Also, the order of
columns contained may not be as deterministic as you think if you use the " SELECT *
FROM t1,t2 WHERE..." syntax.

This is why the mapserver<->postgis connector has the "USING UNIQUE <column>"
clause.  An alternative would be to expect the unique column to be named "fid" -
highly risky, but workable.

Also, the order of tuples returned by the same SQL statement may not be in the same
order.

So, its hard!

dave