Question

1. Suppose that you have been asked to create an information system for a manufacturing plant that produces nuts and bolts of many shapes, sizes, and functions. What questions would you ask, and how would the answers affect the database design? What do you envision the system development life-cycle (SDLC) and Database life-cycle (DBLC) to be?

2. Why do we need databases?

Answer 1

Answer:----------

1). Basically, all answers to all (relevant) questions help shape the database design. In fact, all information collected during the initial study and all subsequent phases will have an impact on the database design. Keep in mind that the information is collected to establish the entities, attributes, and the relationships among the entities. Specifically, the relationships, connectivities, and cardinalities are shaped by the business rules that are derived from the information collected by the designer.

Sample questions and their likely impact on the design might be:-------------

• Do you want to develop the database for all departments at once, or do you want to design and implement the database for one department at a time?
• How will the design approach affect the design process? (In other words, assess top-down vs.bottom-up, centralized or decentralized, system scope and boundaries.)
• Do you want to develop one module at a time, or do you want an integrated system? (Inventory, production, shipping, billing, etc.)
• Do you want to keep track of the nuts and bolts by lot number, production shift, type, and department? Impact: conceptual and logical database design.
• Do you want to keep track of the suppliers of each batch of raw material used in the production of the nuts and bolts? Impact: conceptual and logical database design. E-R model.
• Do you want to keep track of the customers who received the batches of nuts and bolts? Impact: conceptual and logical database design. ER model.
• What reports will you require, what will be the specific reporting requirements, and to whom will these reports be distributed?

The answers to such questions affect the conceptual and logical database design, the database’s implementation, its testing, and its subsequent operation.

What do you envision the SDLC to be?

The SDLC is not a function of the information collected. Regardless of the extent of the design or its specific implementation, the SDLC phases remain:

PLANNING
Initial assessment
Feasibility study

ANALYSIS
User requirements
Study of existing systems
Logical system design

DETAILED SYSTEMS DESIGN
Detailed system specifications

IMPLEMENTATION
Coding, testing, debugging
Installation, fine-tuning

MAINTENANCE
Evaluation
Maintenance
Enhancements

What do you envision the DBLC to be?

As is true for the SDLC, the DBLC is not a function of the kind and extent of the collected information. Thus, the DBLC phases and their activities remain as shown:

DATABASE INITIAL STUDY
Analyze the company situation
Define problems and constraints
Define objectives
Define scope and boundaries

DATABASE DESIGN
Create the conceptual design
Create the logical design
Create the physical design

IMPLEMENTATION AND LOADING
Install the DBMS
Create the database(s)
Load or convert the data

TESTING AND EVALUATION
Test the database
Fine-tune the database
Evaluate the database and its application programs

OPERATION
Produce the required information flow

MAINTENANCE AND EVOLUTION
Introduce changes
Make enhancements

2).

A database is an organized collection of various forms of data. It is also known as a structured set of data that is accessible in many ways through your computer.

The various reasons for which we require databases are:

• To manage large chunks of data
• Accuracy
• Ease of updating data
• Security of data
• Data integrity: Data integrity also becomes a question when storing data in spreadsheets. In databases, you can be assured of accuracy and consistency of data due to the built in integrity checks and access controls.