Re: How to signal a program that a table has changed?

In article <1992Mar6.155810.1_at_vxcrna.cern.ch>, roeber_at_vxcrna.cern.ch writes:
> We are running Oracle on some unix platforms. We would like to have
> a way of arranging for programs to register an interest in one or
> more tables, and then having these programs somehow notified when
> one of these tables changes.

It has been pointed out that I wasn't clear in my posting. Sorry about that. I meant I'd like to have programs notified when the *contents* of a table change -- like when a row has been updated or inserted.

We will have various servers floating around, monitoring hardware and storing the measurements in the database. The tables I'm most interested in will have only one row, for the most recent measurement. Other programs will want to know when this row is updated, because that means there is a new measurement available.

These programs will, e.g., add the data to a graph on a monitor, or store the values in a logging database, or check that the measurements are within limits and raise an alarm if they aren't, etc.

Virtually all of these programs will be in C, using embedded SQL. Some will be preprocessed with Pro*C, others will use the OCI calls directly.

Any new suggestions or ideas would be great. Thanks!

-- 
Frederick G. M. Roeber | CERN -- European Center for Nuclear Research
e-mail: roeber_at_cern.ch or roeber_at_caltech.edu | work: +41 22 767 31 80
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