Code Description

we will describe the function of several primary folders.

• stmt_handler

  The XXX_exec is the executor of each DDL or DML statement. The "stmt_handler" receive every SQL statement, and then parse it to AST, create corresponding XXX executor, and execute.

• sql_parser

  parse every SQL statement into AST.

• logical_operator

  logical expression for every operator of query , like filter, join etc..

• physical_operator

  physical expression for every operator of query, besides, including exchange operator for shuffling.

• loader

  load data into system, like insert and load statement.

• node_manager

  manage state of every node in cluster, master-slave architecture, every slave node connects to master node periodically.

• storage

  manage data in memory.

• common

  auxiliary function.