PLSQL_V2_COMPATIBILITY

Parameter type	Boolean
Default value	false
Parameter class	Dynamic: ALTER SESSION, ALTER SYSTEM
Range of values	true | false

PL/SQL Version 2 allows some abnormal behavior that Version 8 disallows. If you want to retain that behavior for backward compatibility, set PLSQL_V2_COMPATIBILITY to true. If you set it to false, PL/SQL Version 8 behavior is enforced and Version 2 behavior is not allowed.