The event mechanism is by far the most efficient method of keeping your search services up to date. However, if your searches are complex, developing and fully testing your search service may be cumbersome. This is the problem the Pull Mapper sets out to solve.
The pull mapper uses timestamps on application records to find records that have been created or updated since the pull mapper or the extractor last ran. When it finds such records it hands them off to the Search Controller to update the search services, and from here the process is exactly the same as the standard event mechanism. This process requires that all database tables involved in a search service are scanned, which does obviously require database resources. In essence the Pull Mapper sacrifices some runtime performance to provide a quicker and easier way to develop searches.