oracleexclusivelock

oracle 10g支援手動與自動lock，自動lock會鎖定有 ... LOCK TABLE employee IN EXCLUSIVE MODE. (EXCLISIVE ... ROW EXCLUSIVE: 與ROW SHARE相同，但也禁止用於已經被ROW ...

When a statement modifies data, its transaction holds an exclusive lock on data that prevents other transactions from accessing the data.

Exclusive. If a session needs to modify a simple object, then an exclusive lock is required on the resource to prevent any concurrent access.

ROW SHARE permits concurrent access to the locked table but prohibits users from locking the entire table for exclusive access. ROW SHARE is synonymous with ...

The LOCK TABLE statement allows you to explicitly acquire a shared or exclusive table lock on the specified table. The table lock lasts until the end of the ...

Several transactions can acquire shared locks on the same resource. An exclusive lock ensures that there is no more than one active transaction in the database ...

Only one session can take an exclusive lock on a row, or a whole table, at a time. -- First session. UPDATE hr.employees. SET salary = salary * 1.1.

Exclusive locks are used when the programmer desired exclusive control over a set of rows until their operation has completed. The following command is used to ...

2013年4月10日 — Exclusive lock : Only one user/connection are allow to change the data. Update lock : Rows are locked till user made commit/rollback. ... SQL> ...

一般而言，共享鎖定(Share Lock) 比互斥鎖定(Exclusive Lock) 具有更高的資料並行性(Data Concurrency)。在多使用者資料庫系統使用鎖定法(Locks)，有時會產生死結(Dead ...