Re: Relational Algebra and Aggregate Functions

On Mon, 2009-07-27 at 21:05 -0400, Robert James wrote:
> 1) Introduction to Database Systems
>
http://www.amazon.com/Introduction-Database-Systems-Kannan-Swamynathan/dp/B001BVYKY4/ref=sr_1_5?ie=UTF8&s=books&qid=1248742811&sr=1-5
>
> and
> 2) Database in Depth: Relational Theory for Practitioners
>
http://www.amazon.com/Database-Depth-Relational-Theory-Practitioners/dp/0596100124/ref=sr_1_7?ie=UTF8&s=books&qid=1248742811&sr=1-7

I recommend #2. It's shorter and easier to read than "An Introduction to
Database Systems", and I think it will answer your question about
relational theory and aggregates (see "SUMMARIZE").

Appendix A is a part of "Databases, Types, and The Relational Model: The
Third Manifesto". That's interesting, but it's not an easy read, it's
describing a system in formal detail.

Regards,
    Jeff Davis