CHAPTER 9

Two problems of flat file

• Currency of Information

• Task-Data Dependency

• Multiple Updates

• Data Redundancy

what 3 types of data mgmt causes Data Redundancy

Data Storage

Data Updating

Currency of Information

Task-Data Dependency

User’s inability to obtain additional information as their needs change.

The user’s information is constrained.

Adds to data redundancy.

4  Elements of the Database Environment

Users,

DBMS,

Database administrator,

Physical database

DBMS responsibilities

• Program development

• Backup and recovery

• Database usage Reporting

• Database access

Duties of the DBA

• database planning

• database design

• database implementation

• database operation, maintenance

• database change, growth

Unintentional updating of data in a table, resulting from data redundancy

What anomoly occurs because of data redundancy

Update

Internal View

File organization

Indexes

B+ trees

Hashing

Compression

Block sizes

Conceptual View examples

Relationships

Attributes

Constraints

Entities

User View examples

Student

Faculty

Manager

Salesperson.

Crow's Foot Notation

A graphical technique used in ER diagrams to depict cardinality, especially "many" relationships.

Data Model

A visual representation of an organization’s data, illustrating the nature of the data and the business rules governing its use. Serves as a blueprint for the physical database.

Indexed Sequential File

A file structure used by relational databases that uses an index with a sequential file organization to facilitate both direct access and batch processing.