True or False: A single clustering key can contain one or more columns or expressions

• A. False
• B. Depends on data
• C. True
• D. Cannot be

Answer: (C)

Clustering keys can be composite, meaning a single clustering key can span multiple components—columns or expressions. When you define a clustering key with CLUSTER BY, you can include several columns (for example, CLUSTER BY (region, order_date)) or even expressions (such as CLUSTER BY (DATE_TRUNC('MONTH', order_date))). This single key then guides how Snowflake organizes data into micro-partitions to improve pruning for queries that filter on those components. That’s why the statement is true: a single clustering key can contain one or more columns or expressions. The other options don’t fit because the ability to compose a clustering key is not dependent on the data, nor is it an impossibility to have multiple components in a clustering key.