In
studying Databases the following Terminologies must be clear
Data
lThis
is the fact or facts about specific entity (person, place or thing).
Information
lThis
is the processed facts perceived to be useful by the user.
Field
lThis is a single item of
information or data in entity. E.g.
employee Name
Record
l This can be defined as data or group of fields about an
entity. E.g. employee particulars
Subject (relation or table)
lThis can be defined as a
collection of records that are
related to a particular entity. For example, Records for all employees will
make up one subject.
¡
History of Databases
¡Manual systems
¡File Processing Systems (FPS)
¡Database Management systems
(DBMS)
1. MANUAL SYSTEM:
Before the advent of the ideas behind the modern
database systems, it was common for different firm to store information using
manual system.
Structure for manual system
•Information can be
stored in a separate rooms
•Rooms will be
furnished with selves, diff shelves will hold records for different subjects.
•Records will be
stored in a hard files, each fill will carry one record
•Each file will have a
specific number to identify
•A person will use the
file number to retrieve the specific file (record)
•
Manual
systems
2.File processing System (FPS).
¡Information stored as groups of
records in separate files.
¡Consisted of a few data files and
many application programs
¡Each file contained the processed
information for one specific function
¡Use of programming languages to
write applications.
¡Little flexibility.
¡High maintenance.
¡Many limitations.
Limitations
of File Processing Systems
Has laoreet percipitur ad. Vide interesset in mei, no his legimus verterem. Et nostrum imperdiet appellantur usu, mnesarchum referrentur id vim.
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