Re: Database table API supporting incremental view updates

Why database can't notify the listener(s) that a row with PK#1000 from Table Emp has been changed (inserted, updated or deleted)? It is responsibility of the clent to requery the interesting "window" of the data, then.

Technically, in oracle, for example, before java in the database was avaliable database event notification could be implemented through DBMS_ALERT; but today there are probably much more ways to do it.

ciarancarthy_at_hotmail.com (Ciaran Carthy) wrote in message news:<5bf1eb0c.0203060626.1efd35ab_at_posting.google.com>...
> I am wondering is there any research currently which tries to address
> the following problem:
> Java applications which need to show table views of large underlying
> tables, where the data can change dynamically, face many problems
> where the database API is SQL based. When a row in the table changes
> there is no way for the server to tell the GUI how to alter its sort
> order based on a row being added/deleted/modified. Solutions where
> some server based code sends a delta update to the GUI do not fix this
> as they cannot provide the table position of the changed row (assuming
> the server is changing the data through SQL). Solutions where the
> client caches ALL the table data are not allowed for obvious
> scalability reasons.
>
> What could solve the problem is a callback based API where clients
> request a filtered view and the server updates each view individually
> with deltas that are specific to that view. The deltas contain the new
> and old data and the necessary row positions. Obviously it is more
> efficient for the database code to compute these row positions,
> especially in the unfiltered table case.
>
> Is there any ongoing research to standardize on such an API ? I'm even
> looking for a few keywords to help me search the web for something
> useful. For those in the know, what I am looking for is something
> vaguely similar to IMAPITABLE.
Received on Wed Mar 06 2002 - 19:09:18 CET