The EndecaIndexingOutputConfig components specify how to generate records from items in the catalog repository, but the actual generation is performed by data loader components. Depending on your ATG environment, data loading may be an operation that is performed occasionally (if the content rarely changes) or frequently (if the content changes often). To be as flexible as possible, the ATG-Endeca integration provides two approaches to loading the data:

Bulk loading and incremental loading are not mutually exclusive. For some environments, only bulk loading will be necessary, especially if content is updated only occasionally. For other environments, incremental loading will be needed to keep the search content up to date, but even in that case it is a good idea to perform a bulk load occasionally to ensure the integrity of the indexed data.

Note that Oracle Endeca Commerce always does a baseline update after ATG performs bulk loading, and typically does a partial update after ATG performs incremental loading. In some cases, however, Oracle Endeca Commerce may perform a baseline update after incremental loading, because of the nature of the changes. For example, if incremental loading adds a new dimension value, Oracle Endeca Commerce performs a baseline update.

The IncrementalLoader component uses an implementation of the PropertiesChangedListener interface to monitor the repository for add, update, and delete events. It then analyzes these events to determine which ones necessitate updating records, and creates a queue of the affected repository items. When a new incremental update is triggered, the IncrementalLoader processes the items in the queue, generating and loading a new record for each changed repository item.