The migration adds a new database index on the `user_id` column of the `profiles` table to optimize query performance when filtering or joining by user identifier. This change targets the `20230614000001_add_user_id_index_to_profiles.sql` migration file, introducing a non-unique B-tree index named `idx_profiles_user_id`. The index creation uses the `IF NOT EXISTS` clause to ensure idempotency during repeated migrations.
The new index on the `user_id` column in the `profiles` table improves query performance when filtering or joining by user identifier, reducing full table scans during authentication and profile retrieval operations.
