Presently, UPDATE STATISTICS keeps a detailed log of its internal activities if one has specifed "update statistics log on" in advance.
In production scenarios, this is typically not done. That means when a long-running UPDATE STATISTICS command fails on a large table, one has to redo it with logging turned on in order to troubleshoot.
A better practice might be to always log, and delete the log if the operation succeeds.
Another issue with UPDATE STATISTICS logs is their location. The directory is different than other Trafodion logs and is sometimes hard to find. As part of this JIRA, consideration should be given to writing the logs to the Trafodion logs directory instead.