Debugging parameter mismatch across RAC database instances with R, dba_hist, and gv$parameter

Did you find this post useful?  Does your organization need Oracle services?  We can help.   Much of this morning went into investigating strange ADDM reports on a two-node Oracle RAC database.  For some reason, there were statistically improbable differences between impact percentages that have persisted over a month; in this case, instance 2 would