Database

Element 1:

Database Standards:

PC 1.1

To design the database, we can use the following methods:

Physical modelling, Conceptual modelling and logical modelling are three main steps. Various tools can be used to model different kinds of the data:

1. Hierarchical Method

Data is modelled into a tree-like structure and allows 1: M relationship between two different types of data.

2. Network Method

Data is modelled to many to many relationships.

3. Relational Method

Data has to be well organised. Data structures, storage and integrity constraints are well defined.

4. Object Oriented Method

Database stores data and manages the relationships among data elements.

While designing the database following method is usually followed:

* Explore the data to be modelled

* Identify the relationship among the entities

* Superimpose a logical structure upon the data on the basis of these relationships

* Specific the consistency rules among entities

PC 1.2

DBMS Management Issues:

Following are the features on could be selected:

1.) Capacity for large databases

2.) Security

3.) Performance

4.) Additional Features

PC 1.3

LIST - A:

1) Integrity:

To ensure the stored data is accurate and appropriate business rules when operate the database.

a) Domain integrity: The entries in a field or column must be from the same domain.

b) Entity integrity constraint: Each row must be unique, which means the primary key must not duplicated somewhere else and must not be null.

c) Referential integrity: Foreign key must be present in the referenced table.

d) Business rules: This indicates the relationship among entities.

e) Database consistency: All database integrity constraints are satisfied.

2) Security: All data must be protected from all types of threats:

* Accidental Issues – caused by accidents such as mis-operation, power failure, disk failure, or other hardware relating problems.

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