There are database schema changes between 2.1.0 and 2.1.1, and the update scripts to be applied are found in the docs/updating folder of the release.
Migration from an earlier version will require the successive application of all intermediate update scripts. You cannot, for example, move from 2.0.1 to 2.1.1 by applying a single DB script. You will need to move first from 2.0.1 to 2.1.0, and then to 2.1.1.