On the subject of documentation I'd like to say this: I find
PostgreSQL's documentation to be truly excellent (both in accessibility
and depth), and it is one of the main reasons why we use PostgreSQL in
our projects (the quality of the software itself is of course the other
reason).
I certainly wouldn't mind explanations of 'internal' features on a user
level; as others have stated, this may be helpful in understanding the
output of EXPLAIN, as a means of building better databases, or even just
because we are interested but not quite so much that we want to read
source code. And I agree with earlier posters that, now that HOT has
been pushed as a great new feature, it should be properly explained.
People who complain about the PostgreSQL documentation need to wake up:
the documentation of PostgreSQL is one of the best, if not the best,
I've ever seen for an open source project, and other projects should
take it as a shining example of how things should be done.
Hans Guijt