Avg SQL Response Time is calculated as following: elapsed_time/executions (not including current execution), or Average SQL Response Time = SQL statement duration time / SQL statement number of executions
SQL duration time is the elapsed time since the statement has been opened. It is represented by (Statement Active Time + Statement Idle Time). Active Time is the value representing the time frame in which the statement was not idle, meaning it is experiencing a Wait Event e.g. the SQL execution is in I/O wait, CPU wait, CPU Usage etc.
SQL statement number of executions is the value representing how many times the statement has been executed during its duration time. The Average SQL Response Time metric accuracy is really dependent on two factors - detection of SQL duration time and Number of executions of the SQL statement in a given History period.
Elapsed Time, in contrast to Active Time, includes all idle waits, so by definition is greater or equal to Active Time.
