But now you do have some other considerations (see below.) I don't think it's an absolute pancea, but it's certainly a very interesting and very useful secondary point in the design space. I like PlanetScale a lot. The free tier is also actually useful I think.
To be clear even if it's is "serverless SQL" you still have to design with the fact you're using Vitess in mind. So you have no foreign keys, scalability is done by keyspace sharding (not currently available in PlanetScale), apps deal with online migration where the schema evolves as they access it, etc. You have to keep these things in mind but you get some benefits in return, like most things.
I've not played with PlanetScale yet, but I am planning on playing with TerminusDB in the near future.
PlanetScale – Database for Developers - https://news.ycombinator.com/item?id=27197873 - May 2021 (128 comments)
All migrations are automatically executed on production, pre-tested. Reviewed. No DB Administrator, No deployment together with the app.
It works quite well..
However, personally I really like not having to deal with schema changes. For example Firebase or Cloud DataStore is really nice... Its the best for developers, but not for data integrity.
We have some "medium sized" Postgres databases around 1-10TB and something like adding an index to a big table (100s millions of rows) can be quite expensive resource wise
(I'd say "big" is something like 20-50TB+ and small <1TB)
