PostgreSQL 15 introduces several enhancements, including improved sort performance and write-ahead log (WAL) file compression, and is now supported by Neon. One notable feature is the SQL MERGE command, which allows for the updating, inserting, or deleting of rows in a single statement, offering an alternative to the INSERT ON CONFLICT statement that has existed since version 9.5, with differences in handling concurrent insertions. Additionally, PostgreSQL 15 has removed the global CREATE privilege from the public schema to enhance security, requiring explicit permission grants for trusted users. Another enhancement is the ability of unique constraints and indexes to treat NULL values as not distinct, allowing only one NULL in a column specified as UNIQUE. Users are encouraged to explore these features on Neon and consider migrating their projects to PostgreSQL 15.