Standards and portability:\nEvaluate the statement:\n\n"Structured Query Language (SQL) is an internationally recognized standard language that is understood by all commercial DBMS products."

Introduction / Context:
SQL is standardized (ISO/IEC), and most relational DBMSs implement some dialect of it. However, claiming that all commercial DBMS products understand SQL is too strong, because not all commercial databases are relational or SQL-based (consider hierarchical, network, key-value, document, and wide-column stores). Even among SQL products, dialect differences are significant.

Given Data / Assumptions:

• SQL standards exist and many vendors implement large subsets/supersets.
• There are commercial non-SQL databases (e.g., some NoSQL systems) and legacy engines.
• Vendors often extend SQL with proprietary features (PL/SQL, T-SQL, procedural extensions).

Concept / Approach:
Separate two ideas: (1) SQL is standardized and widely adopted among relational systems; (2) not every DBMS is relational/SQL-based, and even among SQL systems, portability is imperfect due to dialects and extensions. Therefore, the universal claim "understood by all commercial DBMS products" is false.

Step-by-Step Solution:

Verification / Alternative check:
Review vendor documentation for non-SQL products or compare SQL dialect compatibility matrices—differences and non-SQL products exist, disproving the absolute claim.

Why Other Options Are Wrong:

• Correct: ignores non-SQL commercial systems and dialect divergence.
• True for relational products only: while often true, the prompt asserts “all commercial DBMS products,” so the correct evaluation is simply “Incorrect.”

Common Pitfalls:
Assuming “commercial DBMS” equals “relational SQL DBMS.” Forgetting that standards do not guarantee perfect interoperability across vendors.

Final Answer:
Incorrect