Which of the following refers to the correctness and completeness of the data in a database ?

Question

Accepted Answer

The correct option is (2):
Data integrity is the fundamental concept in database management that refers to the overall completeness, accuracy, and consistency of data throughout its entire lifecycle. The "correctness" aspect is directly addressed by ensuring data is accurate and valid according to predefined rules, while "completeness" ensures that all necessary data is present and accounted for. A high level of data integrity is crucial because it guarantees that the information used for queries, reports, and decision-making is reliable and trustworthy. Database Management Systems (DBMS) employ various mechanisms, such as integrity constraints, to maintain this high standard of data quality.

The incorrect option is (1):
Data security is the protection of data from unauthorized access, corruption, or theft. Its primary focus is on access control, authentication, and encryption, ensuring that only authenticated users can view or modify the data. While data security prevents external threats from compromising data quality, the term itself does not define the inherent correctness or completeness of the data; it only refers to the mechanisms that protect it.

The incorrect option is (3):
A Data constraint is a specific rule that is set on a column or table to limit the type of data that can be inserted or deleted. Common examples include PRIMARY KEY, FOREIGN KEY, NOT NULL, and CHECK constraints. The role of a constraint is to *enforce* the correctness and consistency of the data. Therefore, a constraint is a *tool* or *rule* used by the database system, whereas data integrity is the *goal* or *principle* that these tools are trying to uphold.

The incorrect option is (4):
Data independence is a concept related to the architecture of the database, describing the separation of the data's definition from the programs that use the data. Specifically, logical data independence means the conceptual schema can change without altering the external views, and physical data independence means the physical storage structure can change without affecting the conceptual schema. This concept relates to system flexibility and maintenance, not the intrinsic quality (correctness and completeness) of the data itself.