*Context diagram *Level 0 diagram *Detailed diagram in database

SUBJECT : DATABASE

 Difference between

*Context diagram

*Level 0 diagram

*Detailed diagram in database

In the field of systems design and database planning, diagrams are used extensively to visually represent the structure and workflow of information systems. Context diagrams, Level 0 diagrams, and detailed diagrams each serve different purposes and provide varying levels of detail about the system. Here's a breakdown of the differences among them:

 

Context Diagram

Purpose: Serves as the highest level view of an information system, presenting the system as a single process.

Content: Shows the system as a whole and its interactions with external entities (users, external systems, and other processes). It illustrates inputs and outputs between the system and external entities.

Level of Detail: Very high-level; it does not include details about the system's internal processes. It's used to understand the system's boundaries and external interfaces.

Use Case: Ideal for stakeholders to get an overview of the system's interactions without being overwhelmed by details

Level 0 Diagram (DFD - Data Flow Diagram)

Purpose: Provides a more detailed view than the context diagram, breaking down the system into major processes.

Content: Identifies the major processes that are carried out within the system, the data flow between these processes, and external entities. It serves as a bridge between the very high-level context diagram and more detailed diagrams.

Level of Detail: Offers a glimpse into the main components of the system but still does not delve into detailed processing steps. It labels and numbers each process and shows data stores for the first time.

Use Case: Useful for understanding the major processes and data flows within the system, serving as a foundation for more detailed analysis.

Detailed Diagram (Can be considered a Level 1 DFD and beyond)

Purpose: To elaborate on the details of each process identified in the Level 0 diagram, potentially expanding further into lower sub-levels (Level 2, Level 3, etc.).

Content: Includes detailed processes, showing exactly how data moves through various parts of the system. These diagrams can show individual data stores, detailed data flows, and processing steps within a particular high-level process.

Level of Detail: Very detailed; provides a comprehensive view of the processes and data flows within the system. Each lower-level diagram decomposes a process from the level above it, adding more detail.

Use Case: Best suited for designers, developers, and analysts who are building or analyzing the system. These diagrams help in understanding and documenting how specific parts of the system work in detail.