What are comments in query expressions used for?

Comments in query expressions serve the primary purpose of providing clarity to the author and others who may be reading or maintaining the code in the future. By including comments, an author can document their thought process, explain complex logic, or highlight specific areas of the query that may require further attention or consideration. This practice is essential for collaborative environments where multiple individuals might interact with the same codebase, ensuring that the intent behind the query is communicated effectively, thus facilitating easier understanding and modification when necessary.

While other options may suggest additional uses for comments, such as executing commands, modifying query behavior, or enhancing performance, these do not accurately represent the true functionality of comments. Comments are typically ignored by the query processor and do not influence execution, performance, or the operational characteristics of the query itself. Their primary role is focused solely on improving readability and maintainability of the code.