In this scenario, a filter "(price=3.0)" is specified in the search operation. In the base entry and the second entry the attribute "price" is not defined, so the filter is not valid and no LDAP entries will be generated.

In the third entry, the "price" attribute is defined, so it will process this entry. Since the "price" attribute belongs to the products source, it starts from there. A search operation is issued against the physical data source using filter price=3.0. Then using the values of the products.categoryId it loads the corresponding categories. After all data have been loaded, it joins the rows and generate the LDAP entries.