relational database definition database (RDBMS - relational
database management system) A database based on the relational
model developed by E.F. Codd . A relational database allows the
definition of data structures, storage and retrieval operations
and integrity constraints . In such a database the data and
relations between them are organised in tables . A table is a
collection of rows or records and each row in a table contains
the same fields . Certain fields may be designated as keys ,
which means that searches for specific values of that field will
use indexing to speed them up. Where fields in two different
tables take values from the same set, a join operation can be
performed to select related records in the two tables by
matching values in those fields. Often, but not always, the
fields will have the same name in both tables. For example, an
"orders" table might contain (customer_id, product_code) pairs
and a "products" table might contain (product_code, price) pairs
so to calculate a given custome