Since JPA does not support the creation of function-based indexes, it should be possible to create a function-based index manually. However, the existence of a function-based index in a schema makes the Hibernate schema migrator fail, because it scans the schema metadata (including the indexes per table) and finds the index columns that use a function (and not a plain table column) returned as NULL, at least in MySQL 8.

This leads to an exception in the schema migrator, which makes the migration and (in case of a Spring Boot application) the whole application fail.

This is an exception excerpt from a Spring Boot application where this happens:

For some more details, see my question here:

My suggestion would be to ignore all indexes where any of the index columns are returned as NULL.

Also see