Re: relational databases
Date: Fri, 7 Jun 2002 01:40:07 -0400
Message-ID: <bKXL8.25118$Ec3.196806705_at_radon.golden.net>
>can someone here give me a brief primer on relational databases? i've
heard the term before, and i'm curious as to what exactly constitutes a
relational database.<
Ignore Waleed and Ambalika. Both of their answers are completely wrong. James' answer is the closest to correct.
First, one must understand the difference between a database and a DBMS: A database is a set of known (or believed) facts suitably represented for machine processing, and a DBMS (short for database management system) is a computer system which manages databases.
A relational DBMS, or RDBMS, is a DBMS that represents all data in a
database as values in relations.
A relation is approximately equivalent to the mathematical concept of
relation. A relation has a header consisting of a set of N named, typed
attributes and a body consisting of a set of N-dimensional tuples where each
tuple dimension value corresponds to one of the named, typed attributes.
One can represent a relation on paper (or on a computer screen) as a table
of values where each row corresponds to a tuple, each column corresponds to
a named attribute and each cell contains some value stored in the relation.
Received on Fri Jun 07 2002 - 07:40:07 CEST