Which database to store big metric data on Raspberry Pi? [closed]
I think SQLite will perform well in this role. You might need to tune the pragma settings a bit for the rPi (e.g. set journal_mode=WAL), but SQLite can easily handle multi-gigabyte databases. (SQLite's main weakness is concurrent access, but that won't be a problem for your application.)
If you only need to store timestamp/value data, and only query on timestamp ranges, you might opt to use a key/value store such as LevelDB. You lose the flexibility of a SQL engine, but you gain performance.
What storage medium are you planning to use? An ACID database will write to the disk for every transaction. Continuous I/O like that can quickly kill an SD-card.