On Sun, Jul 26, 2009 at 12:49:32PM -0500, Kevin Grittner wrote: > Codd, E.F. (1990). The Relational Model for Database Management > (Version 2 ed.). Addison Wesley Publishing Company. > ISBN 0-201-14192-2.
Looks as though I've got some reading to do then--somewhat annoying that only second hand copies available from the US, but never mind! > I believe that he puts forward a list of about 200 things he feels > should be true of a database in order for him to consider it a > relational database. Since he was first and foremost a mathematician, > and was something of a perfectionist, I don't think some of these are > achievable (at least in the foreseeable future) without tanking > performance, but it makes for an interesting read. I find most of it > to be on target, and it gives a unique chance to see things from the > perspective of the inventor of relational model for database > management. Yup, I've heard lots and read a few smaller articles but don't think I've got around to any of his books. > I don't, of course, agree with him on everything. If you think that > the SQL standard date handling is weird, wait until you see how a > perfectionist mathematician attempts to deal with it. :-) Also, the > requirement that, to be considered a relational database, it must be > impossible to write two queries which can be shown to be logically > equivalent but which optimize to different access plans to be, well, a > bit "ivory tower." Sounds as though he's using a different definition than what I would use, but I'm sure I'll find out. -- Sam http://samason.me.uk/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers