Answer: Query pruning

The question asks which Snowflake mechanism limits the number of micro-partitions scanned by a query. Query pruning (Option C) is the correct answer because it is Snowflake's optimization technique that automatically eliminates micro-partitions that do not contain relevant data for a query, based on metadata like min/max values. This reduces the amount of data scanned and improves query performance. The community discussion confirms this with 100% consensus on C, referencing authoritative documentation that explains how query pruning works with micro-partitions. Other options are incorrect: Caching (A) stores query results but doesn't limit micro-partition scanning; Cluster depth (B) relates to clustering efficiency metrics, not a scanning limitation mechanism; Retrieval optimization (D) is vague and not a specific Snowflake feature for micro-partition scanning reduction.

Author: LeetQuiz Editorial Team