Change only one application and database to release 15.0 at a time.
Consider making daily bcp dumps of the databases. To fall back, you can then load the dumps into the earlier server. Keep in mind:
You may need to modify the databases to support incremental bcp dumps.
The earlier server cannot read release 15.0 backup files. You need to create bcp or other scripts to move tables back to the earlier server.
Do not use release 15.0 schema enhancements until the conversion succeeds.
For information about scheduling backups of user databases, see the System Administration Guide.
Ensure that the application test suite addresses both update correctness and performance acceptability. Also ensure that you do the following:
Maintain the directories and libraries for both releases.
Make sure the applications are using the correct server.
After successful validation, consider having users enter production. A good time to do so is after hours or during production lulls.
See Chapter 6, “Ensuring Stability and Performance” for more information on testing.
There should not be any user impact during migration. The more stringent the validation test is, the less likely you will have bridging issues.
The earlier server cannot read release 15.0 backup files. You must create bcp or other scripts to move tables back to pre-release 15.0.
Do not use release 15.0 schema enhancements until the
conversion succeeds.
Be sure to account for any increased release 15.0 memory requirements that apply to your configuration. For more information, see:
The installation guide for your platform for basic RAM requirements.
Details on configuring memory and data caches in the System Administration Guide
The Performance and Tuning Guide for information on how to configure memory for performance.
Here are some additional tips:
Execute performance measurements on a system with similar capabilities.
For a production system, execute the performance suite during off hours.
For a development system, you may want to add a short period to the development schedule for release 15.0 issues.
For a production system, be prepared to postpone or fall back if needed.
Be sure to notify users when you will be taking applications or databases offline.
