"Events" in Informix?
Philippe Requil asked whether Informix has database events like Interbase, where applications register and are notified on changes without polling. Jonathan Leffler said the answer was most probably no and asked for details. Madison Pruet suggested using MQ with IDS. Brice Avila said probably: some events are built in (such as event code 23, log backup request) and triggers can be written, and triggers can fire triggers. No definitive solution.
Auto-generated by Claude from the posts below — may be imperfect; read the full thread.
I use the freeware Interbase database. The Interbase database provides an "event", which allows applications to respond to actions and database changes made by other concurrently running applications, without having to resort to polling the database on a regular basis, or communicating directly with the other applications. Is this also possible with an informix database?
Philippe Requil' wrote: > I use the freeware Interbase database. The Interbase database provides an > "event", which allows applications to respond to actions and database > changes made by other concurrently running applications, without having to > resort to polling the database on a regular basis, or communicating directly > with the other applications. > > Is this also possible with an informix database? Dear Philippe, The answer is most probably "No". Can you provide URLs where the functionality is described? What events are possible? How does an independent process record its interest in the events? How is a process notified when an external event happens? Is it notified when it causes an event to occur? What happens with nested operations - eg in stored procedures or triggers? -- Jonathan Leffler #include <disclaimer.h> Email: jleffler@earthlink.net, jleffler@us.ibm.com Guardian of DBD::Informix v2003.04 -- http://dbi.perl.org/
> Can you provide URLs where the functionality is described? - http://bdn.borland.com/article/0,1410,32340,00.html - Article in The delphi magazine http://www.thedelphimagazine.com/conts/conts108.php > What events are possible? An event can be initiated anywhere, f.e. in triggers (on post, insert, delete, ...) >How does an independent process record its interest in the events? An application must register itself for a particular event. Then the database will send a message to the application when the event occurs. > How is a process notified when an external event happens? Is it notified when it causes an event to occur? In the delphi environment, there is a special component 'TIbEvents", where events can be registered. When the database alerts an event, the 'OnEventAlert' is fired. >What happens with nested operations - eg in stored procedures or triggers? Events are fired while committing.
Would using MQ in conjunction to IDS address this need? "Philippe Requil'" <Philippe@falcon.be.Nospamplease> wrote in message news:4157b500$0$4144$ba620e4c@news.skynet.be... > I use the freeware Interbase database. The Interbase database provides an > "event", which allows applications to respond to actions and database > changes made by other concurrently running applications, without having to > resort to polling the database on a regular basis, or communicating directly > with the other applications. > > Is this also possible with an informix database? > >
Jonathan Leffler <jleffler@earthlink.net> wrote in message news:<4157BA2E.70705@earthlink.net>... > Philippe Requil' wrote: > > I use the freeware Interbase database. The Interbase database provides an > > "event", which allows applications to respond to actions and database > > changes made by other concurrently running applications, without having to > > resort to polling the database on a regular basis, or communicating directly > > with the other applications. > > > > Is this also possible with an informix database? > > Dear Philippe, > > The answer is most probably "No". > > Can you provide URLs where the functionality is described? > > What events are possible? How does an independent process record its > interest in the events? How is a process notified when an external > event happens? Is it notified when it causes an event to occur? What > happens with nested operations - eg in stored procedures or triggers? Philippe, I believe the answer is "probably". Some events are inherent to the database (i.e. event code 23 is a request for a logical log backup) and some events you can write a trigger for (i.e. insert into the "customer" table). And a trigger can spring another trigger. Hope this answers your question. Brice