To make it shorter than OP's reply, from my understanding of the offerings:
- PlanetScale for predictable load. You pick a config (CPU, memory) and if you don't have traffic it sits idle, and if you have traffic it's limited by the config you picked.
- Neon for scalability. You pay for compute hours, so if your traffic is spikey (e.g. concert ticket sales), you don't pay for idle resources during low traffic, and get all the compute you need during high traffic.
Except: "The active time includes periods when the database is receiving requests and for a duration (default 300 seconds) after the last request is received. Following this period of inactivity, the database scales down to zero, effectively pausing compute time billing."
So if you get at least one request every five minutes, neon will charge you for 24 hours of compute a day.
I use Postgres on RDS. Our database is several TB and runs a 24/7 production app. It seems fine. (earnest question) Why should I look into either/both of these?
Some slightly outdated information from PlanetScale [1] Especially now the have Postgres offering as well but most are still relevant. Most people would actually find cost reduction migrating. Similar story with Neon although I am more bias towards PS.
It is not that RDS dont work well. I think it is AWS being too greedy with their pricing and we have finally reached a point where it breaks our mental model on cost evaluation. And people are starting to look at alternatives.
- PlanetScale for predictable load. You pick a config (CPU, memory) and if you don't have traffic it sits idle, and if you have traffic it's limited by the config you picked.
- Neon for scalability. You pay for compute hours, so if your traffic is spikey (e.g. concert ticket sales), you don't pay for idle resources during low traffic, and get all the compute you need during high traffic.