I suppose it means by what is meant by an "observation". Is that an entire time series for a single property or a single point? Nevertheless, the number of points absolutely matters.
A regular Postgres database can give you 50-100K inserts per second and can scale to at least 1B rows with 100K+ individual series without much difficultly. If you know you will need less (or much less) than this, my suggestion is to use a regular table with a covering index. If you need more, use ClickHouse.
A regular Postgres database can give you 50-100K inserts per second and can scale to at least 1B rows with 100K+ individual series without much difficultly. If you know you will need less (or much less) than this, my suggestion is to use a regular table with a covering index. If you need more, use ClickHouse.