SAP LUW and DB LUW

SAP LUW and DB LUM
-(SAP Logic Unit Work)

-LUM Concept
  SAP System Use LUW Concept and Related handling mechanism To Maintain Apllication Database table's Data Consistent.
  In SAP System，Two Data Consistent status's Time Interval Called LUW.
  Every LUW need a Commit or Roolback Set End Flag.
  If Use Commit Set End Flag,So will do all update.and Use Roolback Cancel all database table data update.However,Between In Old consistent status X and new consistent status Y, If have a link or step happening error then must cancel all operation,Rollback to X Status.