QueryEngine

https://github.com/thulab/iotdb/files/6087969/query-engine.pdf

Design ideas

The query engine is responsible for parsing all user commands, generating plans, delivering them to the corresponding executors, and returning result sets.

Related classes

• org.apache.iotdb.db.service.thrift.impl.TSServiceImpl.java

  IoTDB server-side RPC implementation, which directly interacts with the client.

• org.apache.iotdb.db.qp.Planner

  Parse SQL, generate logical plans, optimize logical plans, and generate physical plans.

• org.apache.iotdb.db.qp.executor.PlanExecutor

  Distribute the physical plan to the corresponding actuators, including the following four specific actuators.

  • MManager: Metadata operations

  • StorageEngine: Data write

  • QueryRouter: Data query

  • LocalFileAuthorizer: Permission operation

• org.apache.iotdb.db.query.dataset.*

  The batch result set is returned to the client and contains part of the query logic.

Query process

• SQL parsing

• Generate logical plans

• Generate physical plans

• Constructing a result set generator

• Returning result sets in batches

Related documents

• Query Plan Generator

• PlanExecutor