Integrity controls supported by DBMSs Which of the following integrity controls may be enforced by a DBMS?

Introduction / Context:
Modern relational databases provide rich integrity controls so that correctness does not rely solely on application code. Using built-in constraints shrinks bug surface area and improves data quality by design. This question verifies recognition of common DBMS-enforced controls.

Given Data / Assumptions:

• We operate in a relational DBMS with DDL-defined constraints.
• We can specify defaults, domains/ranges, and NULLability in schema.
• Constraints are validated on insert/update.

Concept / Approach:

Defaults fill in values when none are provided; domain constraints limit values via CHECK or enumerated types; NOT NULL ensures presence. These complement primary/foreign keys and unique constraints, forming a comprehensive integrity layer.

Step-by-Step Solution:

Verification / Alternative check:

Documentation for PostgreSQL, Oracle, MySQL, and SQL Server includes DEFAULT, CHECK, and NOT NULL constraints as first-class features.

Why Other Options Are Wrong:

• Option E is false; integrity should be enforced in the database as well as in application logic.

Common Pitfalls:

• Leaving integrity to the app layer only, risking multiple inconsistent writers.
• Overusing triggers where declarative constraints suffice.

Final Answer:

All of the above.