转自:

How to Identify Hard Parse Failures (Doc ID 1353015.1)
Bug 16945190 - Diagnostic enhancement to dump parse failure information automatically (Doc ID 16945190.8)

This is a diagnostic enhancement that will give an early warning
in the alert log if there are excessive parse failures occuring,and will 
collection information about the failures.
 
The sampling interval for flagging recurring parse errors can be fine tuned with the 
hidden parameter "_kks_parse_error_warning".
By default the diagnostic will dump the parse error along with warning in alert log 
every 100 parse errors for a given sql within a 60 minutes period.
 
If there is already a known parse issue then one can use existing event 10035
to dump similar information.