Phased Cutover

The issues for a phased cutover are described in the following sections:


Change only one application and database to release 12.5 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:

Application test suite

Ensure that the application test suite addresses both update correctness and performance acceptability. Also ensure that you do the following:


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 12.5 backup files. You need to create bcp or other scripts to move tables back to pre-release 12.5.

NoteDo not use release 12.5 schema enhancements until the conversion succeeds.


Be sure to account for any increased release 12.5 memory requirements that apply to your configuration. For more information, see:


For a development system, you may want to add a short period to the development schedule for release 12.x issues.

For a production system, be prepared to postpone or back off if needed.

Be sure to notify users when you will be taking applications or databases offline.