Re: Database callbacks.

From: Roger Snowden <rsnowden_at_IHateSpam.com>
Date: 1997/04/02
Message-ID: <01bc3f77$e8d591e0$096fc589@RSNOWDEN.labinterlink.com>#1/1

> What we've come up so far, was to use a trigger upon insertation on the
> required tables, which will run a stored procedure, that will use the
> PL/SQL UTL_FILE package which allows to write into operating system
> files (or named pipes for that matter).
>
> When the daemon succeeds in reading, it parses the data read, and
> through TCP/IP inform the interested applications.

Sounds like a good application for Oracle pipes. Oracle pipes are not like named pipes. They are simply a fast means of facilitating communication between sessions. Presumably, your client application has a session on the oracle instance, right? The trigger can call a procedure which uses dbms_pipe procedures to send a message to your client application. Your client makes a procedure call, again via dbms_pipe, to get the messge. We benchmarked the pipe facility and found that on a 32 bit Unix machine we get about 400 messages / second. Pretty fast.

There is an article in the April issue of OReview (www.oreview.com) which discusses pipes.

Roger Snowden Received on Wed Apr 02 1997 - 00:00:00 CST