HP Integrity NonStop J-Series - Manual (Page 47)

TASK OVERVIEW
Supplying a Data Base
SUPPLYING A DATA BASE
Before you can execute an application generated by ENABLE, you
must supply a data base consisting of one or more files, as
described below. Refer to Section 3 for information about
developing, describing, and creating a data base for your
application.
What is a Data Base?
A data base is an organized collection of information, usually
stored on a computer system. This information is represented by
data in a standard format for ease of access by one, or by
several application programs. A data base often serves as a
repository for the information needed to perform certain
functions in a commercial, scientific, or business enterprise.
Broadly speaking, the format of data in a data base is composed
of three elements. Fields form the smallest units, describing
one feature of interest. A record is a set of fields used to
describe one complete item. A file is a set of records that
describe similar items.
Fields
The smallest named unit of data in a data base is a field. Each
field has a name and occupies a specific location in relation to
other fields.
Fields can contain data that belongs to one of three broad
categories: alphanumeric, alphabetic, or numeric. Alphanumeric
fields contain data composed of letters of the alphabet, spaces,
digits, and special symbols like the hyphen. Alphabetic fields
contain data composed of letters of the alphabet and space
characters. Numeric fields contain digits, minus or plus signs,
and decimal points.
A group field consists of two or more continguous fields. Each
field within a group field has its own field name. In addition,
the group itself has a name that can be used to refer to all the
fields. As an example, consider a group named "address." This
group consists of fields named "street," "city," "state," and
"zip-code."
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