Soft upgrade allows you to run a newer version of Derby against an existing database without having to fully upgrade the database. This means that you can continue to run an older version of Derby against the database.
If you perform a soft upgrade, you will not be able to perform certain functions that are not available in older versions of Derby. Specifically, new features that affect the structure of a database are not available with a soft upgrade. For a list of the new features in a release, see the Release Notes for that release.
To perform a soft upgrade on a database created using an earlier version of Derby, simply connect to the database, as shown in the following example:
connect 'jdbc:derby:sample'