Question

1. What are ERDs and how are they used?

2. What is data warehousing and data mining?

3. How are permissions used to control access to data?

Answer 1

1.

ERD is entity relationship diagram.

It is a model that represents how entities are related to each other.

Shows the relationship of entity sets stored in data base.

2.

Data warehouse is a system which is used for reporting and analysis of data.

An electronic storage of data by business organizations

It supports business intelligence activities.

There are various stages in data warehousing

Reporting, analysing,predicting, operation,

Active warehousing.

3.

Permissions will determine user ability for performing an action or object.

It is security technique which tells who can access the data.It restricts the unauthorised users from accessing data