Documents created in old versions of Nuxeo DM cannot be found when doing a fulltext search on the title field only

Documents created before the configuration of the ecm:fulltext_title index in the postgresql repository configuration file are not completely indexed hence not suggested by the new searchbox0 suggestion feature introduced in 5.5 nor through the advanced search form (when using the "Title" search field).

We could probably write a SQL migration script for such simple cases involving only simple text fields.

However such migration script would not work for other more complex indices involving binaries or complex properties. For such hypothetical cases a batch re-indexing operation would probably be required at the core repository level.