What is the respective responsibility of TiDB, TiKV and PD (Placement Driver)?

system · January 30, 2023, 7:07am

TiDB works as the SQL computing layer, mainly responsible for parsing SQL, specifying query plan, and generating executor.
TiKV works as a distributed Key-Value storage engine, used to store the real data. In short, TiKV is the storage engine of TiDB.
PD works as the cluster manager of TiDB, which manages TiKV metadata, allocates timestamps, and makes decisions for data placement and load balancing.