Not quite. The performance gain is to bring those features to Postgres!

Edit:

Performance gains are from having the ability to load balance reads (horizontal scaling for read queries) and scale out writes (with sharding). Once instance bottleneck in Postgres has many faces:

1. Behind schedule vacuums because of too many dead tuples (too many writes)

2. The WALWriter is single-threaded and IO-bound - Postgres can only do about 200-300MB/sec in writes per instance (real prod numbers on EC2 with NVMes and ZFS, basically best case scenario).

3. Bulkheading: single primary is a single point of failure. With 12 primaries, if one fails, 91% of your customers don't notice.

The list goes on. Rust is just a side effect. We love it because it's fast and correct - the perfect match for a database product.