How You Plan for Application Issues
To ensure your applications can be tested in the new installation, do the following:
• Before starting the upgrade, take an application and database inventory. You must have the complete and current source code for all applications. If the source code does not match what users are running, problems can result.
• Make sure that each application can be rebuilt from the source code because you will eventually recompile your applications under the new version.
• If an application cannot be rebuilt, test the original executable under Ingres as soon as possible. If the application has no upward compatibility issues (for example, reserved words), it may be possible to run the old application against an Ingres installation and database. Otherwise, you will have to recreate the application or do without it.
• Try to synchronize the test and live Ingres upgrades with an appropriate time in the application life cycle.
If application development is underway, plan how to coordinate new development with Ingres compatibility. Upgrades from newer versions (OpenIngres 1.2 or newer) may be able to move quickly enough to avoid the issue. Preparing an upgrade from Ingres 6.4 can take long enough to rule out a full stop in development.
One site, for example, addressed the timing issue by synchronizing Ingres compatibility with a code release. Then, the development installation was converted to Ingres, while an Ingres 6.4 “bug fix” installation was maintained on a different machine.