1.Cite some examples of integrity constraints that you think should hold on the
database shown in Figure 1.2. 2.1. Define the following terms: data model, database schema, database state, internal
schema, conceptual schema, external schema, data independence, DOL, OML, SOL,
VOL, query language, host language, data sublanguage, database utility, catalog, client/
server architecture.
- Discuss the main categories of data models.
- What is the difference between a database schema and a database state?
4 Describe the three-schema architecture. Why do we need mappings between
schema levels? How do different schema definition languages support this architecture?