Answer: UPSERT

The question asks which DML command is NOT supported in Snowflake. UPSERT is not a valid SQL command in Snowflake - it's a conceptual term that describes the combination of UPDATE and INSERT operations, but Snowflake implements this functionality through the MERGE command instead. MERGE is fully supported in Snowflake and can perform UPDATE, INSERT, and DELETE operations. UPDATE is a standard DML command supported in Snowflake. TRUNCATE TABLE is considered a DML operation in Snowflake (unlike some other databases where it's DDL), and it is supported. The community discussion consistently confirms that UPSERT is not a valid command in Snowflake, with multiple users selecting A as the correct answer and explaining that MERGE serves the UPSERT functionality.

Author: LeetQuiz Editorial Team