Dumb RDBMS for my study

Done

CREATE DATABASE, CREATE TABLE, INSERT, UPDATE, SELECT, INNER JOIN
Persist to Disk (Wal and Snapshot)
Transaction (with OCC)
Multiple process (goroutine)
Test

TODO

Replication (with Raft)
Persist (Distribution, multiple write in one transaction)
Multi-tenant (Send tenant-id with SQL and not read other tenant's data)
Index
Remove panic
Abort ambiguous column identifier (SELECT id FROM a, b)