Re: Database and push channels

Jonathan Leffler wrote: > > >From: Donny Tjandra <donnyt@lri.ucsf.edu> > >Date: Mon, 14 Jul 1997 12:53:26 -0700 > >X-Informix-List-Id: <news.40403> > > > > I am seeking a way to subscribe to a row in a table in a database. > > When the row is updated or deleted, I get automatic notification by > > email, fax, phone, etc. Can any database product do this, and if not > > how would one go about implementing something like this? > [SNIP] > > This could easily be horribly inefficient -- you wouldn't want to do it on > every table in your main OLTP database. > Yeah I aggree, not on *every* table, but there are specific applications.... "Push" technology is horribly inefficient! (Outside of certain specific instances.) See Teknekron Information Bus (TIB) in ACM circa '90 or so. However, there are several applications which this makes sense. 1) Trading Industry. (CBOE/CME/CBOT clearing house security applications) [Or even private brokerage firms which need to limit trading activity.] 2) General Security applications. How many times has a certain record been accessed. Who has tried to access this information and they don't have the correct permissions. Send an alert. 3) Any automated control system with soft/hard high/low watermarks. As the data gets updated, if a watermark is hit, then an alert. 4) ANY SMTP tool like Openview. Store the results in a database, and if an error occurs in the network map, an alert occurs. Actually all very efficient use of Stored proceedures and Triggers. Of course, come to think of it, none of these examples are truely "push" technology. I realize that I am rambling, but "push" technology, aka publish and subscribe, is more like this: I have a stream of real time data to hit the database, it is stored, and evaluated. The "cleansed" data from the database is then "pushed" to the various subscribers. (Broadcast data). It is then determined if this is the data you want to see and presents it to you. On the internet, push technology is inefficient and a waste of bandwidth because the percentage of users who will find this information, or who will have access to this information will be a small population. On an intranet, this is different and the data/technical means of hits a greater percentage of recipients who find this data usefull. I guess what I am trying to say in a long rambling way, is that the original poster isn't talking about "push" technology. "Push" technology is just another misused buzz word. FWIW, TIS (Teknekron Information Systems) is now part of Reuters. -Mikey "I think I stopped making sense a long time ago" -- #include <std_disclaimer.h> /* Mike Segel (MS385) */ #include <No_Spam.h> #ifdef OFFENDED_BY_CONTENT The author takes no responsibility for this post. Any resemblence to a coherent rational thought is purely coincidence. -The Management. #endif ***************************** Due to AGIS's Refusal to Act Responsibly We are blocking all of their domains at the packet level. This block will exist until AGIS modifies their policies to conform to existing RFCs and net community standards. We encourage all ISPs and domain holders to do the same. *****************************