Sometime you may want to know if a index exists on a certain field. You can use the db4o-meta information to find out if a field is indexed.
StoredClass metaInfo = container.ext().storedClass(IndexedClass.class); // list a fields and check if they have a index for (StoredField field : metaInfo.getStoredFields()) { if(field.hasIndex()){ System.out.println("The field '"+field.getName()+"' is indexed"); } else{ System.out.println("The field '"+field.getName()+"' isn't indexed"); } }