Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> writes:
> Interestingly, the paper is mentioned in the bibliography of the
> official PostgreSQL documentation. Apparently there's a good primer on
> relational theory, SQL and PostgreSQL history.
Most of that material is still in the source tree, though it seems it's
not being built into the official docs at the moment --- see
doc/src/sgml/sql.sgml
As a guide to hacking the backend, though, I wouldn't recommend it.
It's too outdated, and IIRC we had to rip out and redo large parts
of the original INTERSECT/EXCEPT patch.
regards, tom lane