Question

1. Explain the rules and style guidelines for creating entity relationship diagrams (ERDs).

2. Create an ERD. (Create a detailed ERD diagram with proper development)

3. Describe the use of a data dictionary and metadata.

4. Explain how to balance ERDs and data flow diagrams.

5. Describe the process of normalization.

With references

Answer 1

Entity Relationship Diagrams (ERDs) are graphical tools used to illustrate the relationships between entities in a system. A data dictionary provides attribute descriptions and metadata is data about data. Normalization is a technique for structuring databases to reduce redundancy and improve integrity.

Step-by-step explanation:

Entity Relationship Diagrams (ERDs)

ERDs are graphical representations that illustrate the relationships between entities within a system. Here are some rules and style guidelines for creating ERDs:

• Use rectangles to represent entities, and label them with singular nouns.
• Use diamonds to represent relationships, and use verbs to label them.
• Use lines to connect entities with relationships, and add cardinality notation (such as 1:N or M:N) to indicate the types of relationships.
• Incorporate attributes, represented by ovals, and connect them to their respective entities.

To create an ERD:

1. Identify all the entities involved in the system.
2. Determine the relationships between these entities.
3. Add attributes to each entity and describe the nature of the data.

Data Dictionary and Metadata-

A data dictionary provides a detailed description of each attribute in the database, which includes data type, size, allowed values, and data meaning. Metadata is data that describes other data and is used to provide context and meaning to data.

Balancing ERDs and Data Flow Diagrams-

Balancing ERDs and data flow diagrams (DFDs) involves ensuring that the data stores represented in DFDs match the entities in the ERDs, representing a coherent system. This requires communication between database designers and systems analysts to align the two diagrams.

Normalization Process-

The process of normalization is a technique to structure a relational database in such a way that it reduces redundancy and improves data integrity. It involves applying a series of rules called normal forms, starting from the First Normal Form (1NF) and potentially going up to the Fifth Normal Form (5NF).