[wcarss]

Thanks for taking the time to look into it, that's an interesting point. According to the manual [1], InnoDB's insert locking should not prevent other inserts from executing, it only takes an exclusive row lock on the inserted row. I agree that measuring would likely be smart.

This makes some intuitive sense, though: general purpose databases are expected to be _pretty good_ at handling the case of "add new data" with no other specific conditions, e.g. on other rows or tables' existing data.

I also agree with your last point. Running count() all day on this wouldn't be great, and compaction would take real time. I assumed that most high throughput write scenarios for something like an event count or view count can be a few minutes (or hours, or days) out of date, at which point read caching would be my first stop before clever summation algorithms, which are still pretty cool.

1 - https://dev.mysql.com/doc/refman/8.0/en/insert.html