In SQL administration, which statement is used to recompile an existing view so that its definition is validated and metadata is refreshed?

Introduction / Context:
Views depend on underlying tables and other objects. When dependencies change, some DBMSs require recompilation to validate the view definition and refresh its execution metadata. Identifying the correct statement for recompiling an existing view is a common administrative skill.

Given Data / Assumptions:

• We are working with an existing view.
• We need to recompile or revalidate it without dropping and recreating.
• SQL dialect conventions use ALTER statements to modify existing objects.

Concept / Approach:
The correct approach is to alter an existing object. In many platforms, the statement is ALTER VIEW (for example, ALTER VIEW view_name COMPILE in Oracle, or ALTER VIEW view_name AS … in SQL Server to refresh the definition). “CREATE VIEW” defines a new view; “COMPILE VIEW” and “DEFINE VIEW” are not standard SQL statements.

Step-by-Step Solution:
Confirm object state: the view already exists.Choose the SQL verb for modifying existing objects: ALTER.Apply to the object type VIEW: ALTER VIEW … (possibly with COMPILE in dialects that support it).

Verification / Alternative check:
DBMS documentation shows that view maintenance tasks use ALTER VIEW for recompilation/refresh. In information_schema-based systems, you may need to reissue the view definition via ALTER VIEW to update metadata after schema changes.

Why Other Options Are Wrong:

• CREATE VIEW: Creates a new view; does not recompile an existing one.
• COMPILE VIEW / DEFINE VIEW: Non-standard commands.
• None of the above: Incorrect because ALTER VIEW is valid.

Common Pitfalls:
Dropping and recreating a view unnecessarily (which can cascade permissions), or assuming a simple SELECT from the view forces recompilation—some systems cache plans that require explicit alter/refresh.

Final Answer:
ALTER VIEW