And don't forget that pipes are local to an instance, so 1) think carefully about your pipe naming convention (for example, if you want schema-specific pipes, prefix the pipename with the username) 2) you can't coordinate work across multiple RAC instances using DBMS_PIPES. DBMS_PIPE is also a great (lightweight) way to coordinate work done in the database with remote external processes and agents (eg a C program running on a remote host). You only need an Oracle client on the remote host. Regards Nigel ----- Original Message ---- From: rjamya <rjamya@xxxxxxxxx> To: cosmini@xxxxxxxxxxxxxxx Cc: oracle-l@xxxxxxxxxxxxx Sent: Wednesday, May 2, 2007 12:41:45 AM Subject: Re: asynchronous PL/SQL development; DBMS_AQ ?? The only problem with pipes is once they are clogged, sending process will appear to hang. If you handle that, it should work fine. AQs will maintain data if instance crashes, pipes will loose them. rjamya On 5/1/07, Cosmin Ioan <cosmini@xxxxxxxxxxxxxxx> wrote: ahh... I knew I had read it somewhere, already... that's what happens when you have 30+ books on Oracle-everything ;-) ... you loose track of "who-dunnit" ;-) thx for the reference reminder, Alberto ;-)