In Oracle, LOCK TABLE statement is used to lock tables, table partitions, or table subpartitions.
To commits all changes into the database table, use the following syntax:
Parameters:
tables: The comma delimited table name.
lock_mode: The loack mode.
WAIT: To specifies wait to acquire a DML lock.
NOWAIT: To specifies not to wait for a lock to be released.
| Lock Mode | Description |
|---|---|
| ROW SHARE | Allows concurrent access to the table, but users are prevented from locking the entire table for exclusive access. |
| ROW EXCLUSIVE | Allows concurrent access to the table, but users are prevented from locking the entire table with exclusive access and locking the table in share mode. |
| SHARE UPDATE | Allows concurrent access to the table, but users are prevented from locking the entire table for exclusive access. |
| SHARE | Allows concurrent queries but users are prevented from updating the locked table. |
| SHARE ROW EXCLUSIVE | Users can view records in table, but are prevented from updating the table or from locking the table in SHARE mode. |
| EXCLUSIVE | Allows queries on the locked table, but no other activities. |
Note:
In the above example would lock the suppliers table in SHARE MODE and not wait for a lock to be released.