Data Engineering Associate with Databricks Practice Exam

What is the purpose of constraints in Delta Lake?

1. To restrict the data types of columns

2. To enforce data integrity and quality

3. To optimize query performance

4. To automatically back up data

The correct answer is: To enforce data integrity and quality

The purpose of constraints in Delta Lake is primarily to enforce data integrity and quality. Constraints allow for the definition of rules that the data must adhere to, ensuring that it remains accurate, consistent, and valid across the dataset. By implementing constraints such as unique constraints, primary keys, and NOT NULL constraints, Delta Lake helps maintain the reliability of data, which is crucial for making informed decisions based on that data. Using constraints allows data engineers to set specific requirements for data entries, preventing the introduction of invalid data into the system. This mechanism is essential in data management as it safeguards against common issues like duplication, missing values, and data type mismatches, ultimately leading to higher-quality data processing and analysis. While the other options touch upon aspects of data management, they do not capture the primary role of constraints in Delta Lake as effectively. For instance, while some may consider that constraints could limit data types, this isn't their main function. Similarly, the potential for optimizing query performance and backing up data pertains to different features of the data platform rather than the specific purpose of constraints.