The Guided Search incremental indexing feature requires that changes to repository data be tracked for use by future incremental indexing processes. All repository changes for all servers are stored on a single datasource which, out of the box, is configured to be the ATGProductionDS datasource. During incremental indexing, each server uses its own instance of the /atg/search/repository/IncrementalItemQueueRepository component to access the tracked changes on the ATGProductionDS datasource and perform the indexing updates. This means that all servers require access to the ATGProductionDS datasource in order to do incremental indexing. Out of the box, the ATGPublishing and ATGProduction servers have access to the ATGProductionDS datasource but the ATGStaging server does not. Follow the procedure for your application server below to add the ATGProductionDS datasource to the ATGStaging server instance.