A relationship between a date column on a fact and the Qlik Compose date dimension can only be created during the Star Schema wizard to create the star schema. It is not possible to add a relationship from a date column on the fact to the date dimension after the star schema is created.
It is desirable to add the functionality to link a date column on the fact entity in the star schema to the date dimension after the star schema is created. The 'Add dimension to star schema' button allows an existing non-date dimension to be added to a star schema after the star schema is created, but this is not possible for a date dimension to another date column on the fact.
If the entity model changes and a new date column is added to the entity, it will not be possible to add a link from that date column in the star schema of that entity to the date dimension. The Star Schema would have to be dropped and recreated, which is not optimal, particularly when there may be millions of fact records.
