Create a partial covering index for movies with rating at least 4.0, ordered by genre then release_year, with title available from the index. Explain one selective query that repeats the partial predicate and one that omits it.
Expected: for genre = 'Drama' and release_year = 1981, the matching query can use an Index Only Scan and report few heap fetches; the query without rating >= 4.0 cannot rely on that partial index. The order matters when a query filters a genre and ranges over years.