Resource locking purpose: does it prevent multiple applications from taking simultaneous write copies of the same record that is about to be changed?

Introduction / Context:Locking is a classic mechanism to preserve consistency under concurrent access. This question asks whether locking exists to prevent conflicting, simultaneous modifications of the same data.

Given Data / Assumptions:

• Concurrent transactions may target the same row/page/table.
• Without coordination, “lost updates” and inconsistent reads can occur.
• DBMSs use locks (or MVCC with conflict detection) to serialize or validate writes.

Concept / Approach:Yes—locking (especially pessimistic locking) prevents multiple writers from updating the same record at once. Even in MVCC systems, write-write conflicts are prevented or detected, and one transaction typically must wait or be rolled back to avoid corruption.

Step-by-Step Solution:Identify conflict: two sessions intend to change the same row.Apply locking rule: acquire a write-intent lock; others block or validate later.Result: only one change is committed; the other is serialized or rejected.

Verification / Alternative check:Simulate two concurrent UPDATEs under READ COMMITTED with row locks; the second updater waits until the first commits/rolls back.

Why Other Options Are Wrong:Calling the statement invalid ignores the fundamental purpose of locking; restricting to table-level or certain engines is unnecessary.

Common Pitfalls:Confusing read locks with write locks; assuming MVCC “removes” locking—it still coordinates writers.

Final Answer:Valid statement