Database Concepts - Database Design Phases

The figure below shows a simplified description of the database design process. 

When developing some databases, we find different phases. They are

1 - Requirements collection

2 - Requirements analysis

3 - Design

4 - Implementation (application program)

Requirements collection

The first step shown is Collect requirements. During this step, database designers interview potential database users to understand and document their data requirements. 

Example: Imagine that we are building a database for a bookstore, in this case the developer will have to interview the entities of that bookstore to collect the necessary requirements for the creation of the database.

Here the developer's MINI WORLD is the Bookstore, because your goal is to develop a database for this Bookstore.

Requirements Analysis

Requirements Collected requirements is combination of database requirements and functional requirement, so designers analyze the collected requirement and come up with formatted database and functional requirement.

Example:

Database requirements (back-end) (Oracle, MySql, etc)

Book database -> id, title, author, publisher,pub_in, copies

Author database -> id, author_name, contact

Publisher database -> id, author_name, address, contact

Functional requirement (front-end) (Web, Mobile, Desktop)

Functional means what kind of interface we will use to communicate with the database (back-end)

Design ( schema conceptual for database requirements)

Here the designer presents a conceptual schema.

This step is called conceptual design. That it is a concise description of user data requirements and includes detailed entity descriptions such as types, relationships, and constraints; 

Example:

    

Logic scheme (mapping)

Conceptual schemes are not mapped (connected).

Mapped conceptual schemas are called a logical schema.

Ex:

Physical Project (Internal)

Schema Logical:  Schema are stored on the Physical Storage Media

Internal Schema provides information about the schemas of the storage structure in which location

Now the backend is ready.

Functional analysis

Based on the functional requirements (about operations and interface), the designer analyzes the functional requirement and presents a number of forms.

created form (Transaction) are also stored on the stored physical media

Now the front-end is ready

Implementation (application program)

Based on the back-end logical schema (database) and the front-end transaction (function) , the application programmer writes the actual code (program) to implement the ready bookstore database package

Now the bookstore database is ready