To view the shape of an execution plan and analyze the plan, perform the following steps:
EXPLAINcommand to view the shape of the execution plan, or view the cached execution plan by real-time execution plan display. For more information, see Introduction to SQL execution plan and Real-time execution plan display.
Analyze the execution plan to determine whether your selection of the index, join order, and join algorithm is reasonable and correct. For more information, see Access path, Join order and Join algorithms.