OLTP systems are operational systems, or transaction processing systems. These systems directly support the operational process. Examples of OLTP systems are ERP, MES or MRP systems. Besides OLTP systems, there are EIS / DSS systems. These provide managers with information. OLTP systems have different requirements for the underlying database than DSS systems. The database for OLTP systems should be optimized for writes and small reads. The database for DSS should be optimized for reading large numbers of records.