I know Ethereum uses leveldb. When I checked into EOS I could not find that much out. I thought when I tested I did see leveldb.
Can someone confirm how the immutable data is stored?
I think people may be misreading my question.
In Ethereum, LevelDB is used to store all the blocks as they are built. This therefore provides a history. If I want to know what were the older values of a variable, I could check in LevelDB.
It seems people have misread my query to be what dbs are supported by EOS?
EOS must be storing data somewhere which would be then open to queries. Hence someone can find out how a variable changed. Otherwise they will just see a variable value. The whole point - in my view - of using a blockchain is that we can see the old values. This is a sort of audit.
Therefore, my question is how would I query a db in EOS to get the old values of the state variables?