SUMMARY 2022/2023
,DBLC – Database Life Cycle.
Basically, a database is a carefully designed and constructed repository of facts. The
database is a part of a larger whole known as an information system, which provides for
data collection, storage, and retrieval.
Systems analysis is the process that establishes the need for and the extent of an
information system. The process of creating an information system is known as systems
development.
DBLC – Database Life Cycle.
DBLC has 6 phases:
database initial study,
database design,
implementation and loading,
testing and evaluation,
operation,
maintenance and evolution.
The overall purpose of the database initial study is to:
Analyse the company situation.
Define problems and constraints.
Define objectives.
Define scope and boundaries.
Interactive and iterative processes required to complete first phase of DBLC successfully
,Analyze the Company Situation
• Analysis–To break up any whole into its parts so as to find
out their nature, function, and so on
• Company situation
– General conditions in which company operates, its
organizational structure, and its mission
• Analyze company situation
– Discover what company’s operational components are, how
they function, and how they interact
Define Problems and Constraints
• Managerial view of company’s operation is often
different from that of end users
• Designer must continue to carefully probe to generate
additional information that will help define problems
within larger framework of company operations
• Finding precise answers is important
• Defining problems does not always lead to perfect
Solution
Define Objectives
• Designer must ensure that database system objectives correspond to those envisioned by
end user(s)
• Designer must begin to address following questions:
, – What is proposed system’s initial objective?
– Will system interface with other existing or future systems in the
company?
– Will system share data with other systems or users?
Database Design
Database Design
• Necessary to concentrate on data
• Characteristics required to build database model
• Two views of data within system:
– Business view of data as information source
– Designer’s view of data structure, its access, and activities required to transform
data into information
• Loosely related to analysis and design of larger system
• Systems analysts or systems programmers are in charge of designing other system
components
– Their activities create procedures that will help transform data within database
into useful information
• Does not constitute sequential process