Propagate Documentation
Talend Data Catalog enables the propagation of documentation (including Name and Business Definition, diagrams, join relationships and custom attributes) from older versions of a model. This propagation of the documentation is now always enabled.
When you check the Propagate documentation checkbox, Talend Data Catalog does not change behavior, and documentation changes made to any historical version are still propagted to new versions. If you leave this checkbox unchecked, the same behavior is true.
Basically, the behavior is that a change to a version applies to any later versions. However, there is an exception when dealing with relationships from or to the imported model and its contained objects.
When the latest version of the model already contains the proper change, going to an older version that does not have the change and updating it can have unintended side effects. For relationships this is a bit tricky as one must deal with cardinality as well. So in the case where the link is unary, the latest version has the unary link to a particular object, and trying to create the unary link in the older version to a different object means deleting the existing link in the latest version. In this case
- When these versions have the link we create the link in the old version but not propagate it to newer versions.
- Otherwise we propagate it to newer versions when it is unavailable there.
This feature can produce conflicts and unexpected results. For example, when you edit the same piece of documentation in different versions the latest edit wins. It is true even when you edit the latest version first and an old version later. You should disable the feature after you finish making future-proof changes to older versions to avoid unnecessary conflicts.