DOA and Oracle Alerts

[carmas]

We have been using DOA components for more than a year, and we are very confortable with them. Our application is a suite for PMS (Property Management Systems) compound of more than 10 modules (Windows applications).

We have been facing some deadlock situations. When we check the Oracle trace files, we find a lot of the deadlocks more or less related to Oracle alerts. In fact, we make an intensive use of them to implement the refreshment of data grids in a multiuser environment.

We are not sure if we have some missunderstanding of the issue or it is a problem with the Oracle DBMS_ALERTS package, or, eventually, there is a bug on the implementation of the alerts code on DOA.

Our configuration is
- Delphi 6 Enterprise Edition
- Oracle 8.1.7
- DOA 3.4.6.4

Best regards,

Carlos de Armas

 

[Marco Kalter]

The dbms_alert.signal procedure will indeed cause a lock on the signal (see the "Oracle Supplied Packages" manual for details).

This implies that you can also cause deadlocks through the usage of dbms_alert.signal calls, so you have to design your transactions so that they cannot block each other.

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Marco Kalter
Allround Automations