Incremental Harvesting

Some bridges are capable of incremental harvesting as they can detect what has changed in the source technology and therefore only import what has changed (updated or new). Enabling this feature offers much faster subsequent harvesting, and much less space utilization. Even with incremental harvesting, a new version of the imported model will be produced if there are changes or if Create new versions only when new import has changes has been specified in the Import Options tab. Nevertheless, the produced new version simply reuses (from preceding model version) everything that has not changed.

For those bridges with this capability, it is enabled by default. If you wish to override this default behavior and import everything, changed or not, from the source, you may either:

• Import manually (IMPORT button in MANAGE > Configuration) and check the Yesradio button for theFULL SOURCE IMPORT INSTEAD OF INCREMENTAL.\
• Add the “-cache.clear” option to the _Miscellaneous_ bridge parameter and future imports (include scheduled ones) will NOT take advantage of incremental harvesting.

Exceptions

Some metadata sources do not provide enough information for the incremental harvesting algorithms to determine if there have been changes without complete harvesting the source and then comparing with the cache of the previous imports. In particular:

MySQL JDBC import

MySQL does not store the last time a view was re-defined (Altered) in the database metadata. They recommend using a trigger to track this information. In this case, the bridge will count views in order to know there are differences, but skip their last modification time.