• Updating a Secondary Data Source in InfoPath Using AJAX: ASP Alliance
  Microsoft Office InfoPath does not offer out-of-the-box persistence of data in secondary data sources; only data within the Main data source is persisted. To make updating secondary data sources possible, changes have to be saved back to the underlying source of secondary data sources. This article shows how you can use AJAX to update the data of a secondary data source.
  in InfoPath Web Service with infopath microsoft offer office out-of-the-box persistence service web

out-of-the-box from all users