Re: [SQL NOTIFY Help] sending NOTIFY to the external program

Yes, our application is supposed to know *immediately* that a change in
the database has occurred since, based on this modified data it is doing
lot of other operations and also, the db transactions are heavy(expected
to be arround 300 tps(transactions per sec)).

I agree that this can be done using some untrusted languages, written to
a file and then the application can look into the file for the modified
date. But, as far as performance is concerned it will take time for the
application to get the response. The user on the application side might
not be kept in waiting state until this transaction happens.

Thanks in Advance,
Ramachandra B.S.

-----Original Message-----
From: Richard Huxton [mailto:dev(at)archonet(dot)com]
Sent: Wednesday, January 03, 2007 7:39 PM
To: Ramachandra Bhaskaram (WT01 - IP-Multimedia Carrier & Ent Networks)
Cc: pgsql-sql(at)postgresql(dot)org
Subject: Re: [SQL] [SQL NOTIFY Help] sending NOTIFY to the external
program

ramachandra(dot)bhaskaram(at)wipro(dot)com wrote:
> Hi Richard Huxton,
>
> Thank you for your kind response.
>
> Is there not any other way other than record the pkey in a
> "process_these" table and have the application check there. We want
> to minimise the database transactions to improve the DB performance.
>
> Can we send the exact data which has been changed using
> db-notify to the application? So that, the application can continue
> processing the data using the Notify message from the DB.

Not via your database connection.

With one of the untrusted languages (C, pl/perlu pl/pythonu etc) you
could do anything you could make a separate connection / write to a file
etc.

Does your application need to know *immediately* that a change in the
database has occurred?

--
Richard Huxton
Archonet Ltd

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