What is the role of a contract in data validation?

• A. A legal agreement with vendors.
• B. A formal agreement specifying the validity rules for data types and constraints.
• C. A contract to schedule jobs.
• D. A contract to share data publicly.

Answer: (B)

In data validation, a contract defines what valid data looks like and what rules it must obey. It serves as a precise, machine-checkable agreement that lays out data types, allowed values and ranges, required fields, nullability, formats, and even referential integrity. With this contract, a data pipeline can automatically verify each incoming record before it moves downstream, catching issues early and ensuring consistency across systems. For example, a contract might require that a customer_id is a non-null integer, an email follows a standard format, and a timestamp is in ISO 8601 format. If a record breaks any of these rules, it can be rejected or flagged, preserving data quality and trust in analyses. This role is different from a legal agreement with vendors, a schedule contract, or a data-sharing agreement, which govern relationships or processes rather than the actual validity of the data.