Close is a wrapper function on e.Close(), it handles some common codes.

NewBaseExecutor creates a new BaseExecutor instance.

NewFirstChunk creates a new chunk to buffer current executor's result.

Next is a wrapper function on e.Next(), it handles some common codes.

Open is a wrapper function on e.Open(), it handles some common codes.

RegisterSQLAndPlanInExecForTopSQL register the sql and plan information if it doesn't register before execution.

RetTypes returns all output column types.

TryNewCacheChunk tries to get a cached chunk.

BaseExecutor holds common information for executors.

Executor is the physical implementation of an algebra operator.