relational database management system
Англо-русский словарь компьютерных терминов:
relational database
реляционная база данных, реляционная БД
смотри
RDBMS
Англо-русский политехнический словарь:
relational database
реляционная база данных
Free On-line Dictionary of Computing:
relational 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
customer's bill you would sum the prices of all products
ordered by that customer by joining on the product-code fields
of the two tables. This can be extended to joining multiple
tables on multiple fields. Because these relationships are
only specified at retreival time, relational databases are
classed as
dynamic database management system
.
The first commercial RDBMS was the
Multics Relational Data Store
, first sold in 1978.
INGRES
,
Oracle
,
Sybase, Inc.
,
Microsoft Access
, and
Microsoft SQL Server
are well-known database products and
companies. Others include
PostgreSQL
,
SQL/DS
, and RDB.
["Managing Data Bases, Four Critical Factors" Michael
M. Gorman, QED Information Sciences, Inc.].
["An Introduction To Database Systems" (6th ed) C. J. Date,
Addison Wesley (an excellent source of detailed info)].
["An End-User's Guide to Data Base" James Martin, Prentice
Hall (excellent place to begin learning about DBMS)].
(2002-06-10)
