ompanies like Oracle. Relational databases
are based on the mathematical field of set theory.  The term "relation"
is really just a synonym for "set" -- a relation is just a set of
records or, in our terminology, a table. One of the main innovations in
early relational systems was to insulate the programmer from the
physical organization of the database. Rather than walking through
arrays of records or traversing pointers, programmers make statements
about tables in a high-level language, and the system exe