Is the entire blockchain kept in memory? Putting aside pool mining, does the Bitcoin mining program keep the entire blockchain in memory? Including transactions?
I've been reading through the original Bitcoin code and it looks like the entire chain is kept in memory. Of course that code is over 10 years old, so I'm sure it's changed quite a bit, but I'm still curious.
The original Bitcoin code base definitely didn't support this.
Currently it's possible to effectively keep the entire UTXO set in memory in Bitcoin Core if you set the database cache large enough (over 6 GB, last I checked). The blockchain itself is always stored on disk.