Hive driver wait time is fixed for task getting executed in parallel.

During a command execution hive driver executes the task in a separate thread if the task to be executed is set as parallel. After starting the task, driver checks if the task has finished execution or not. If the task execution is not finished it waits for 2 seconds before waking up again to check the task status. In case of task with execution time in milliseconds, this wait time can induce substantial overhead. So the execution thread can call notify to interrupt the wait call. This will make sure that the next thread execution can start immediately.