The document discusses database management systems and their components. A DBMS is used to create and maintain the structure of a database to store, manipulate, and retrieve data. It provides functionality like data storage, security, multi-user access, backups, and data integrity. When developing a DBMS, the system development life cycle is followed, which includes phases like analysis, design, implementation, and maintenance. Entity-relationship modeling is also used to design databases by identifying the entities, attributes, and relationships between entities, such as one-to-one, one-to-many, and many-to-many.

1. Database Management
System

2. What is a Database?
• It’s a storage structure that provides
mechanisms for recording manipulating
and retrieving data.

3. What is a DBMS?
• Used to create and maintain the structure
of a database, and then enter, manipulate
and retrieve the data it stores.

4. Database Terminology
• Character
• Field
• Record
• File
• Column
• Row
• table

5. Database management System
• Functionality:
– Data storage
– Security
– Multiuser access
– Backup
– Data Access language
– Data integrity
– Data Dictionary

6. System Development Life Cycle
• System investigation
• System analysis
• System Design
• System implementation
• System Integration and testing
• System deployment
• System maintenance and review

7. Entity- Relationship (E-R) Model
 One to one – In a one to one relationship, each occurrence of data in one
entity is represented by only one occurrence of data in other entity. For
example, each classroom is assigned to only one academic division, one-to-
one relationship to create is created between the classroom and division
entities.
 One to many – In one-to-many relationship, each occurrence of data in one
entity can be represented by many occurrence of the data in other entity.
For example, a class has only one instructor but an instructor might teach
many classes.
 Many to many – In many to many relationship, data can have multiple
occurrences in both entities. Example a class can consist of more than one
student and a student can take more than one class.

8. Example of E-R Model
• > Customer can place multiple orders, but each order can be placed by only one
customer (One to many). The dashed line between customers and orders means a
customer can exist in the database without having a current order
• stored in Orders table.
• > An order can consist of more than one book, and a book can appear on more than
one order (many to many)
• > A book can have more than one author, and an author can write more than one
book (many to many)
 A book can have only one publisher, but a publisher can publish more than one book
(one-to many).
 Identifying entities and relationships in the database design process is important
because entities are usually represented as a tables, and relationships can reveal
whether additional tables are needed in the database. If the problem arising from
many-to may relationship in the E-R model isn’t apparent to a designer at this point, it
will become clear during the normalization process.