How many core Codd's rules are commonly referred to in DBMS/RDBMS, excluding…
2017
How many core Codd's rules are commonly referred to in DBMS/RDBMS, excluding the foundational Rule 0?
Answer: C. 12 — In 1985, E. F. Codd published twelve numbered rules (Rule 1 through Rule 12) that define what a system must satisfy to be called a true relational database…
- A.
10
- B.
11
- C.
12
- D.
13
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Correct answer: C
In 1985, E. F. Codd published twelve numbered rules (Rule 1 through Rule 12) that define what a system must satisfy to be called a true relational database management system (RDBMS), along with an additional foundational statement, Rule 0, which requires that the system manage all its data exclusively through relational capabilities.
Because the question explicitly asks for the count excluding the foundational Rule 0, only the numbered Rule 1 through Rule 12 are counted, giving a total of 12 core rules — the set commonly called "Codd's 12 Rules" in DBMS/RDBMS study material and exams.
10: falls short of the numbered set (Rule 1 to Rule 12); no standard listing stops at ten rules.
11: also falls short of the numbered set by one rule; not a standard count.
12: matches exactly the numbered set Rule 1 through Rule 12, i.e. the core rules excluding Rule 0 — this is the count asked for here.
13: only arises when Rule 0 is counted as a separate, additional statement alongside Rule 1 through Rule 12 — but this question explicitly excludes Rule 0, so 13 does not apply here.