Question

Which of the following is wrong?

Select one:
a. A relation includes a foreign key matching the primary key of other relation is called an insertion anomaly
b. If the removal of data in one entity results in the unintentional loss of data in another entity is deletion anomaly
c. A relation is in 2NF if and only if it is in 1NF and all non-key attributes are determined by the entire primary key
d. The condition that a non-key attribute determines another non-key attribute is known as transitive dependency

Answer 1

All the listed statements a, b, c, and d are factually correct regarding database normalization, including insertion anomaly, deletion anomaly, Second Normal Form (2NF), and transitive dependency. Thus, the question does not have a clearly wrong answer based on the provided information.

Step-by-step explanation:

The question is related to database normalization and the identification of certain conditions, or "anomalies," that may arise when database tables are not designed efficiently. Here is a review of each option:

• a. A relation that includes a foreign key to match the primary key of another relation can indeed introduce an insertion anomaly if it causes data to become scattered or if certain data cannot be inserted without the presence of other data.
• b. A deletion anomaly occurs if the removal of data in one entity unintentionally results in the loss of data in another entity. This typically happens when multiple types of information are stored in a single table, and deleting one piece also deletes related information that should have remained.
• c. A relation is in Second Normal Form (2NF) if it is in First Normal Form (1NF) and all non-key attributes are fully functionally dependent on the primary key. This means no non-key attribute should depend on a part of a composite primary key, which is a correct statement.
• d. The condition that a non-key attribute determines another non-key attribute is indeed known as a transitive dependency. This condition is one of the focus points when converting a database schema from 2NF to Third Normal Form (3NF).

Based on these explanations, all statements are factually correct in the context of relational databases and database normalization. However, if one is written incorrectly within the specific context or contains a logical flaw, additional context from the question would be needed to identify which one is "wrong." Without additional context, we can assume that all given options are generally correct in regards to database normalization concepts.