[tsukaisute]

There seems to be a lot of confusion in the other posts as to what this is.

Simply, it is an adapter that lets you use SQL syntax to introspect Ethereum blockchain data (blocks, and transactions.) Typically people do this using a JS API built into the node software [1], and it may/may not be ones' cup of tea.

[1] https://github.com/ethereum/wiki/wiki/JavaScript-API

[xiaoyao]

Yes, and with presto you can join tables from different sources. So you can join ethereum data with whatever you want, be it a mysql table of accounts in observations, etc.