Lock with dbms_alert

Hello everybody,

We have a problem with dbms_alert functionnality :

A batch program on 1 db do a distributed insert on a table (tab_vol) located on a 2nd db (we us db links)
A trigger is firing when rows are inserted in this table (tab_vol) and this trigger insert into another table (tab_tcf) always on the 2n db.
Another trigger is firing on this table (tab_tcf) and do a dbms_alert to notify
a process.

Sometime we have an error for the first transaction on the first db : ORA-2049: timeout: distributed transaction waiting for lock ORA-6512: at "SYS.DBMS_ALERT", line 396 It seems like the dbms_alert on the 2nd db is waiting for a lock but we don't see why ?

Can someone explain me how to use dbms_alert and the role of the commit with this use ?

Can we used dbms_alert in a trigger ?

Can we replace dbms_alert by dbms_pipe, the goal is only to advertise a process to do something ?

What the difference between dbms_pipe and dbms_alert in this case ??

Thanks for your answers

Regards
Olivier Received on Mon Jan 11 1999 - 07:40:13 CST