Relational Databases — What Is a SQL View? Which description correctly identifies a view in SQL and how it is accessed?

Introduction:A view is a powerful logical construct in relational databases that provides a named query result as if it were a table. Views are essential for abstraction, security, and simplifying complex queries by encapsulating joins and filters behind a stable name.

Given Data / Assumptions:

• Standard SQL supports CREATE VIEW and allows querying views with SELECT (and sometimes DML under constraints).
• Views are commonly non-materialized logical definitions; some systems also support materialized views.
• The question targets the core idea of a view, not advanced variants.

Concept / Approach:Conceptually, a view is a saved SELECT statement. When you query the view, the DBMS typically expands or rewrites the query into the underlying base tables. Because it is logical, a view is not a base table by default and does not store data permanently (unless it is a materialized view, which is a separate feature in many systems).

Step-by-Step Solution:1) Identify whether a view is base or virtual: it is virtual by default.2) Determine whether it is accessible via SQL: yes, views are queried with standard SQL statements.3) Therefore, the correct description is a virtual table accessible through SQL.

Verification / Alternative check:DBMS documentation shows CREATE VIEW syntax and demonstrates SELECT * FROM MyView; operating identically to tables from a user perspective for read operations, subject to permissions.

Why Other Options Are Wrong:

• Cannot be accessed via SQL: False; SQL is the interface.
• Base table: A base table is physically stored; a normal view is not.
• Permanent physical copy only: That describes materialized views, which are distinct from standard logical views.

Common Pitfalls:Confusing standard views with materialized views, or assuming all views are updatable. Updatability and performance depend on DBMS rules and the view definition.

Final Answer:A virtual table that can be accessed via SQL commands