Database Administration COMSATS INSTITUTE OF INFORMATION TECHNOLOGY, VEHARI

Roles in the database environment  Data administrator  Database administrator  Database designers (logical and physical)  Application programmers  End users

Roles in the database environment  Data administrator Working area that plans, organizes, describes and controls data resources development and execution of architectures, policies, practices and procedures that properly manage the full data lifecycle  Database administrator IT professional responsible for the installation, configuration, upgrading, administration, monitoring, maintenance, and security of databases in an organization Basic purpose: To improve the efficiency and capacity issues

 Database designers (logical and physical) Who describes the process of producing a detailed data model of a database  Application programmers write code for software applications Single or work in a team  End users

Roles with respect to access There are two ways that roles in a database environment can be used: User roles Application roles

Roles with respect to access User role: A user role is created for a group of database users that have several privilege requirements in common Application role: Application roles are granted when it is necessary for running a database application.

Levels of database architecture There are three levels of database architecture: 1.External level 2.Conceptual level 3.Internal level

Levels of database architecture EXTERNAL LEVEL How data is viewed by an individual user CONCEPTUAL LEVEL How data is viewed by a community of users INTERNAL LEVEL How data is physically stored

Entity- relationship model Entities are real-world objects about which we collect data Attributes describe the entities Relationships are associations among entities Entity set – set of entities of the same type Relationship set – set of relationships of same type