Tell about database design — three levels (conceptual, logical, physical). How detailed was the physical level?

Database design is traditionally divided into three levels:

• Conceptual level — describes the overall data structure and relationships without technical details. Usually, these are ER diagrams reflecting business entities and their relationships.

• Logical level — transforms the conceptual model into a schema suitable for a specific type of DBMS (e.g., relational). Here, tables, fields, keys, constraints, normalization are defined.

• Physical level — describes how data will be stored on physical media: file structure, indexes, partitioning, performance settings.

Regarding the detailing of the physical level, it usually includes:

• Types of indexes and their placement
• Storage parameters (e.g., tablespaces in Oracle)
• Partitioning parameters
• Caching and buffer settings

The level of detail depends on the project requirements and the DBMS used. In large systems, the physical level is developed very thoroughly to optimize performance.