I want to know how to implement a logical comparison using Snowflake utilities to compare source and target data, identify changes, and add old records with close dates and new active records. Can you explain this scenario, and how SNFKT values are used?

In Snowflake you can use a combination of staging tables, hash functions, and the MERGE statement to implement a logical comparison between source and target. First, load the source data into a temporary staging table. Compute a hash (e.g., SHA256) of the business key and all non‑key columns to create a comparison fingerprint. Next, join the staging table to the target (the "current" table) on the business key. For each row, compare the hash values: if they differ, the row has changed. Use a CASE expression to set an "is_active" flag: set the existing target row’s is_active to 0 and close_date to the current timestamp, then insert the new row with is_active = 1 and open_date = current timestamp. The SNFKT (Snowflake Key Tracking) values can be used as surrogate keys or as part of the hash to ensure uniqueness. Finally, wrap the logic in a MERGE statement so that inserts, updates, and deletes are handled atomically. This approach keeps the target table in sync with the source while preserving historical records for SCD type 2.