Upon further investigation:
If, in the following query that is being passed to Postgresql from the ODBC driver, the table named 'pg_user' were to be replaced the table named 'pg_shadow', then the query would work, returning 72 rows.
query='select relname, usename, relhasrules from pg_class, pg_user where relkind = 'r' and relname !~ '^xinv[0-9]+' and int4out(usesysid) = int4out(relowner)order by relname'
[ fetched 0 rows ]
Where to go from here.....??
Perhaps I'm overlooking an ODBC configuration problem.
Chay Wesley