Which entity is created as a result of decomposing a relation while resolving a many-to-many relationship?

In the context of relational database design, resolving a many-to-many relationship typically involves creating an intermediate entity, also known as a junction table or associative entity. This intermediate entity acts as a bridge between the two entities that have the many-to-many relationship.

The primary purpose of the intermediate entity is to break that complex relationship down into two one-to-many relationships, which simplifies data management and improves query performance. For instance, if you have two entities, say Students and Courses, where each student can enroll in multiple courses and each course can have multiple students, the intermediate entity would hold references (usually as foreign keys) to the student and course entities. This structure not only resolves the many-to-many relationship but also allows for additional attributes specific to the relationship, such as enrollment dates or grades.

The other options do not accurately describe what is created when decomposing a many-to-many relationship. A parent key refers to a primary key in a parent table, a primary key is a unique identifier for records in a table that ensures entity integrity, and a null value represents the absence of a value in a field. None of these concepts directly relate to the process of creating an entity to handle many-to-many relationships.