upsert.sql

INSERT INTO … 
SELECT * FROM temp_staging_table -- first prepare the data by preloading into a temp table
ON CONFLICT … DO UPDATE SET … -- upsert on the primary key
WHERE updated_at <= excluded.updated_at -- ensure idempotent jobs
  AND ( -- only write new distinct data
    column_1 IS DISTINCT FROM excluded.column_1 OR 
    column_2 IS DISTINCT FROM excluded.column_2 OR
    …
  )