Re: Database Pipes:Opinions ?

> We are trying to determine the feasibility of relying on the
> the "database pipes" in Oracle7 to activate a Pro*C-program in the Client
> from within the Server. On a given condition a database trigger is
> fired and the trigger in turn sends a "START" message through a database pipe.
> A Pro*C program running at the Client end waits on the database pipe and starts
> running some routines as soon as the "START" word is received.
>
> We are using Oracle7 (7.0.15.4). Our concern is to identify and weigh
>the advantage/disadvantages of relying on the database pipes scheme before it
>can be used for production purposes in our shop.
 

>Somnath Mishra

DBMS_PIPEs should work nicely for you. We produce commercial Oracle system management tools and rely on database pipes in some of our products. Once you figure out how to make them work and understand their limitations, they are extremely reliable. I would mention that the performance of pipes gets better sometime after version 7.0.16 - although I don't know exactly which.

Advantages: Easiest way for synchronous communication between Oracle sessions. Few restrictions on data types. Timeouts can prevent hangups. Easy way to get unique session-specific pipe name for one to one communication. Can easily do one-server multiple-clients.

Disadvantages: If DBMS_PIPE is public executable then communications are insecure and unreliable - practice safe pipes: USE A WRAPPER! No way to start a listener process on the server. Since the listener is always logged in, gotta provide a way to shut it down or else Oracle SHUTDOWN will hang waiting for it. Can only get one unique pipe name per session.

Mail me directly if you have any further questions.

                                                Dave Trahan
                                                BrainTree Technology, Inc
                                                p00775_at_psilink.com