In any database that has more than one user, you will eventually have to deal with locking conflicts when two or more users try to change the same row in the database.
In this section, we present an overview of how locking works in the Oracle database, how users are queued for a particular resource once it is locked, and how Oracle classifies lock types in the database.
At the end of this section, we show you a number of ways to detect and resolve locking issues; we also cover a special type of lock situation: the deadlock.
Locks prevent multiple users from changing the same data at the same time. Before one or more rows in a table can be changed, ...