To learn new Database, I always prefer to start with How it executes the given SQL/Task? For Greenplum MPP database, here is my finding on How it works: 1. Client connect to Postmaster process 2. Postmaster process spawns a background worker process, Query Dispatcher (QD) 3. Then Client submits the SQL’s for execution to QD 4. Query Dispatcher (QD) : one who, a. Works only on master as driving and coordination process b. Takes care of Optimizing the SQL using catalog data c. Create execution Plan d. Write the changes, DTM context to WAL e. Co-ordinate Distributed transac...
Thinking Through Technology.... To design any system put your Business Standard and Technology together keeping them rightly disjoin....