Database Development and Administration

Database Administrator (DBA)

• In charge of enterprise database development
• Improves the integrity and security of organizational databases
• Uses Data Definition Language (DDL) to develop and specify data contents, relationships, and structure
• Stores these specifications in a data dictionary or a metadata repository

Data Dictionary

• Contains data about data (metadata)
• Relies on specialized software component to manage a database of data definitions
• Contains information on:
  • The names and descriptions of all types of data records and their interrelationships
  • Requirements for end users’ access and use of application programs
  • Database maintenance
  • Security

Database Development Phases

• Data planning process
• Database design process
• Data resource management

Data Planning Process

• Develop an enterprise model that defines the basic business process of the enterprise
• Define the information needs of end users in a business process
• Identify the key data elements that are needed to perform specific business activities (entity relationship diagrams)

Entity Relationship Diagram

• Represents data relationships in a business process

Database Design Process

• Data relationships are represented in a data model that supports a business process
• Logical design:
  • Schema: overall logical view of relationships
  • Subschema: logical view for specific end users
  • Data models for DBMS
• Physical design:
  • How data are to be physically stored and accessed on storage devices

Logical and Physical Database Views

• Logical view: represents data relationships and structure
• Physical view: represents how data is physically stored and accessed

Data Resource Management

• Uses data management, data warehousing, and other IS technologies
• Manages data resources to meet the information needs of business stakeholders
• Data stewards:
  • Dedicated to establishing and maintaining the quality of data
  • Need business, technology, and diplomatic skills
  • Focus on data content

Types of Databases

• Operational databases
• Distributed databases
• External databases
• Data warehouses

Operational Databases

• Stores detailed data needed to support business processes and operations
• Examples: customer, human resource, inventory

Distributed Databases

• Copies or parts of databases stored on servers at multiple locations
• Improves database performance at worksites
• Advantages:
  • Protection of valuable data
  • Data can be distributed into smaller databases
  • Each location has control of its local data
  • All locations can access any data, anywhere
• Disadvantages:
  • Maintaining data accuracy
• Replication:
  • Look at each distributed database and find changes
  • Apply changes to each distributed database
  • Very complex
• Duplication:
  • One database is master
  • Duplicate the master after hours, in all locations
  • Easier to accomplish

External Databases

• Databases available for a fee from commercial online services, or free from the Web
• Examples: hypermedia databases, statistical databases, bibliographic and full text databases
• Search engines like Google or Yahoo are external databases

Hypermedia Databases

• Contains hyperlinked pages of multimedia
• Interrelated hypermedia page elements, rather than interrelated data records

Components of Web-Based System

• Web browser (or client)
• Web application server
• Database server

Data Warehouses

• Stores static data that has been extracted from other databases in an organization
• Central source of data that has been cleaned, transformed, and cataloged
• Data is used for data mining, analytical processing, analysis, research, decision support
• Data warehouses may be divided into data marts:
  • Subsets of data that focus on specific aspects of a company (department or business process)

This quiz covers the role of a Database Administrator (DBA) in improving database integrity and security, and their use of Data Definition Language (DDL) to develop and specify data structures. It also touches on the importance of data dictionaries in storing database specifications.