What is a key part of implementing data integrity in a database?

Implementing data integrity in a database primarily focuses on ensuring the accuracy, consistency, and reliability of the data stored. Enforcing rules on data values is essential to this process, as it establishes constraints and guidelines that dictate what data can be entered and how it should be formatted.

For instance, by using validation rules, you can restrict inputs to acceptable data types (like integers for age or specific formats for dates), define ranges (such as a temperature that cannot logically exceed certain extremes), and enforce relationships between different data elements (for example, making sure a foreign key exists in a related table). These constraints prevent erroneous or inconsistent data from being entered into the database, thereby maintaining its integrity over time.

In contrast, using passwords for user access and regularly backing up data are important aspects of security and disaster recovery but do not directly contribute to the integrity of the data itself. Similarly, creating multiple copies of data can help with data availability and redundancy, but it does not inherently improve the accuracy or validity of the information stored. Thus, enforcing rules on data values is a cornerstone of maintaining data integrity within a database.