Nigel, Thank you, yes, the trigger uses DBMS_PIPE. I will pass that on to the developers and see what they have to say. Thanks. Bill Wagman Univ. of California at Davis IET Campus Data Center wjwagman@xxxxxxxxxxx (530) 754-6208 ________________________________ From: Nigel Thomas [mailto:nigel_cl_thomas@xxxxxxxxx] Sent: Monday, January 29, 2007 10:05 AM To: William Wagman Cc: oracle-l Subject: Re: What does an app need to do to work with RAC >>This is done using a trigger and a pipe from the accounts database ... >>I can perform updates to from one node but not the second node. Bill - is the system using a DBMS_PIPE kind of pipe? That only works within the context of a single instance (in 9i, 10g or any other release). If you have pipe 'sources' - ie calling send_message() - on an instance, you need 'sinks' - calling receive_message() - on the same instance. http://download-uk.oracle.com/docs/cd/B10501_01/appdev.920/a96612/d_pipe .htm#998100 and http://download-uk.oracle.com/docs/cd/B19306_01/appdev.102/b14258/d_pipe .htm#sthref5327 both start: "The DBMS_PIPE package lets two or more sessions in the same instance communicate. " HTH Regards Nigel