A Composite Primary Key Is

question 83

Multiple Choice

A composite primary key is:

• A)a merged field containing the primary key and descriptive information.
• B)a key in the intersecting relation that contains the primary keys from the two intersecting relations.
• C)a field composed of information from multiple sources.
• D)a unique field that can be used throughout the organization to identify an entity.

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Definitions:

Nephridia

Excretory organs in many invertebrates, responsible for the removal of waste products from an organism's body.

Lancelets

Small, fish-like marine animals belonging to the subphylum Cephalochordata, known for their role as a model organism in evolutionary biology.

Nephridiopores

External openings of the nephridia, which are excretory organs in many invertebrates, allowing waste to exit the body.

Nephridia

Excretory organs in many invertebrates, including annelids and mollusks, that filter fluid directly from the body cavity.