Information Technology Exam

SMGT 335

Exam 2

Lorie LaPorta

How does a relational database organize data, and how does it differ from on object-orientated database? (10 points)

Relational databases are organized into two-dimensional tables called relations with rows and columns. Each business entity will have its own table. For instance, one table is used for suppliers, and another table used for customers. Object orientated databases are more versatile. Not only do they include images, drawing and photographs and other features, object-orientated databases are capable of retrieving graphics and multimedia applications, whereas relational databases strictly deal with rows and columns which is limiting.

Define and explain the significance of entities, attributes and key fields.

- Entities: a generalized category representing a person, place or thing on which information is stored and maintained. The significance of an entity is that it defines a group or category from which data can be pulled.

- Attributes: defines specific details about a particular entity. The significance of an attribute is that it relates it to its entity, further defining it to finer details.

- Key fields: a field or column in a record that uniquely identifies instances that record so that it can be retrieved, updated, or sorted. The significance of key fields are that key fields are primary keys and a unique identifier that cannot be duplicated.

Define a relational database and explain how it organizes and stores information.

A relational database is a two-dimensional model that organizes information into tables by columns and rows. The columns contain attributes and fields and the rows contain records and tuples. It is capable of relating data in one table to data in another table if there is a common thread or data element for which it can relate.

Explain the role of entity-relationship diagrams and normalization in database design.

Entity-relationship diagrams illustrate...