When showplan is turned on, and abstract plan association mode has been enabled with set plan load, showplan prints the plan ID of the matching abstract plan at the beginning of the showplan output for the statement:
QUERY PLAN FOR STATEMENT 1 (at line 1). Optimized using an Abstract Plan (ID : 832005995).
If you run queries using the plan clause added to a SQL statement, showplan displays:
Optimized using the Abstract Plan in the PLAN clause.