Final answer:
Surrogate keys are artificial keys used in databases for pragmatic reasons, such as ensuring data integrity and consistency and improving performance.
Step-by-step explanation:
Surrogate keys are often used in databases for pragmatic reasons. One of the main reasons is to ensure data integrity and consistency. Surrogate keys are artificial keys that are created specifically for the purpose of identifying records in a database table. They are independent of any attributes of the records themselves, which makes them less prone to changes.
For example, let's say we have a database table that stores information about students, and we use the student's Social Security Number (SSN) as the primary key. However, if a student changes their SSN for any reason, it would result in cascading updates throughout the database. By using a surrogate key, such as an auto-incrementing number, as the primary key instead, we avoid these potential issues.
Another reason for using surrogate keys is performance. Surrogate keys are typically smaller in size compared to natural keys. This means that indexing and searching for records using surrogate keys can be faster and more efficient. Surrogate keys also simplify and streamline relationships between tables in a database by eliminating the need for complex composite keys.