view = join(rel_1, rel_2) --assertains join criteria based on primary keys
filtered_view = select(condition_list, view)
result = project(attribute_list, filtered_view)
Ignoring for a minute that SQL is the accepted method of talking to databases, and also acknowledging that SQL may be more expressive than relational algebra, I wondered if it would be possible to extend Postgresql to allow non-sql interfaces to simple database services.
I suppose it would be possible to convert statements like those above into their SQL equivalent before passing them to an existing driver, but from reading the docs, it seems that dbmses usually do these types of operations once they have parsed the SQL anyway.
I'd be interested to hear your thoughts on the subject whatever they are. Critical comments are particularly welcome (they might be quite useful for getting this stupid idea out of my head ;-)).
Regards, Andy
---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings