[chillycurve]

Database reads/writes are really hard (read: impossible) to predict unless you are already in production. Leading to thoughts like: "1 Billion reads!! I'll never use that much..." Once you cross the line, the overages kick in.

That being said, this does appear to be absurdly cheap compared to competitors. Amazon Aurora appears to be sitting at around $200 a month for 1 billion reads, excluding writes/transfer/storage/etc.

CockroachDB Serverless includes 250M "request units" (request units include reads and writes and individual requests can costs multiple units depending on size). They charge an extra $1 per month per 10M "request units," so $75 to get to 1B reads at least.

Am I missing something? What's the catch?

[throwusawayus]

You're mixing up I/O-based pricing with rows-based pricing. Aurora is priced based on I/O operations, with 16KB pages: https://aws.amazon.com/rds/aurora/faqs/

If you're doing a range scan query and your rows are reasonably-sized, you can conceivably get tens of rows to maybe even a few hundred rows per single I/O operation. Or even 0 I/O operations if the pages are already in memory in the buffer pool cache.

Planetscale prices based on rows.. And scanning a few FAQs I don't see anything about cached rows being free, but maybe i missed it.