Oracle also uses locks to control concurrent access to data. When updating information, the data server holds that information with a lock until the update is submitted or committed. Until that happens, no one else can make changes to the locked information. This ensures the data integrity of the system. Oracle provides unique non-escalating row-level locking. Unlike other data servers that “escalate” locks to cover entire groups of rows or even the entire table, Oracle always locks only the row of information being updated. Because Oracle includes the locking information with the actual rows themselves, Oracle can lock an unlimited number.
