Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
> A more ambitious project, and one which seems to me worthwhile, would be
> a descriptive tour of the source code and data structures.
Have you looked at Bruce's presentations? There are a couple of sets of
slides available from http://developer.postgresql.org/. They're
probably not up-to-date in detail, but the overview doesn't change very
quickly ...
regards, tom lane