On Fri, 27 Mar 2009, Mauro Bertoli wrote: > SELECT > db1.a.id FROM db1.a > UNION > db2.b.id FROM db2.b > > Where "db1" is a database and "db2" is another database. "a" is a > table in database "db1" and "b" is a table in database "db2" You might be able to create the equivalent of a union by having a front-end program connect to both databases. You can have two open connections and query them in turn and put the union together. Particularly if it is just a union of keys. But the essential idea is that the database is the universe of data. E.g. you want to minimize data redundancy in a db, but you wouldn't want to do that across databases, because they are different, independent worlds. What is the business of one is not the business of the other. A query like the above seems to defeat this idea. What you are calling databases, or what the other DBMS calls databases, arguably are not. -- Elle -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
