Se> (MVCC) An advanced technique for improving multi-uSer databaSe performance. The main difference between multiverSion and lock modelS iS that in MVCC lockS acquired for querying (reading) data don' t conflict with lockS acquired for writing data and So reading never blockS writing and writing never blockS reading. ThiS technique iS uSed in the free Software databaSe PoStgreSQL. (1999-06-18)