After upgrading the version of iDash from 12.0.01 to 12.0.04, following error message is seen in the info.log file:
17-09-26 06.10.26 [ERROR] idashdb-schd-update-thread-1:com.ca.idash.core.averageruntime.service.AverageRuntimeUpdater: update average runtime failed
com.ca.idash.core.exception.IdashException: java.sql.SQLException:ORA-00039: error during periodic action
ORA-04036: PGA memory used by the instance exceeds PGA_AGGREGATE_LIMIT
In Oracle Database 12c, a new parameter called PGA_AGGREGATE_LIMIT sets a hard limit on the amount of PGA taken up by an instance. When the overall PGA occupied by all the sessions in that instance exceed the limit, Oracle kills the session holding the most untunable PGA memory, releasing all PGA memory held by that session. That killed session gets this message.
You can use following SQL statement to find actual value of PGA_AGGREGATE_LIMIT :
show parameter pga;