According to the temporary file location to produce the cartesian product of SQL methods
1) is designed.the gn layer, there is a table in the performance_schema session_memory_usage_info

2) query the table, including temp_space field is said takes tmpdata space size, ID field said SQL execution the ID of the

3) then show the processlist designed.the gn layer can be found in the corresponding SQL, then according to the node of SQL to find the corresponding gc layer of SQL