The following message stack is a generic example:
ORA-06502: PL/SQL: numeric or value error ORA-06512: at "SCOTT.VALUE_ERR", line 1 ORA-06512: at line 1
The following message stack is a VAX/VMS example:
ORA-01034: Oracle not available ORA-07625: smsget: $MGBLSC failure %SYSTEM-W-NOSUCHSEC, no such (global) section
In this example, notice that the message at the bottom of the stack is issued by the VMS operating system. Seeing the messages at each level in the system may help you trace the originating event. For example, in this case, Oracle may not be available simply because it has not been started, and consequently there is no system global area (SGA). If you need the help of customer support, be sure to report all the messages in the stack.