Which of the following is true about selecting a clustering depth for a table?

• A. system$clustering_depth returns the depth metric for the table.
• B. system$clustering_depth is used to retrieve the clustering ratio.
• C. system$clustering_depth retrieves clustering information for specific columns.
• D. system$clustering_depth modifies clustering depth.

Answer: (A)

Clustering depth is a diagnostic measure of how well data in a table aligns with its clustering keys. The system$clustering_depth function provides that depth metric for the table as a single numeric value, reflecting how deeply the pruning tree would need to traverse during a query. This is a read-only metric and does not modify anything, nor does it return per-column details or a clustering ratio. So, the description that system$clustering_depth returns the depth metric for the table is the accurate one.