If you specified the SHOW_THREAD_PERF statement in the dbmover.cfg configuration file, this message reports the amount of time, in microseconds, that the joiner thread spent performing

I/O

for the partitioned session. The message reports the average, minimum, and maximum

I/O

times over the specified number of rows. When the joiner is not performing

I/O

, it waits for the partitions to complete processing.