During processing the database differences with liquibase.diff.DiffResult, the methods addMissingIndexChanges and addUnexpectedIndexChanges ignore indexes associated with foreign key constraints. Since Oracle does not generate indexes on foreign key constraints, the indexes are missing in a Liquibase generated database.
After removing the skip condition
the missing update steps will be generated correct for Oracle databases.
Fixed as part of 3.0 changes. Tested against 3.0.6 and is working
http://forum.liquibase.org/topic/bug-core-1236-should-be-reopened#49382000001055031 says it is still broken
am working with liquibase on an Oracle database (220.127.116.11.0). Among the changes between two DB, we have added index on foreign keys which are not mentionned in the DIFF.
We are at version 3.1.1 so the problem should be fixed by  since version 3.0.6, but it still occurs. Do you have non regression test to assert this point is solved?