UNLOCK TABLE statement

Use the UNLOCK TABLE statement in a database that does not support transaction logging to unlock a table that you previously locked with the LOCK TABLE statement. The UNLOCK TABLE statement is an extension to the ANSI/ISO standard for SQL.

Syntax


Element	Description	Restrictions	Syntax
`synonym`	Synonym for a table to unlock	The synonym and the table to which it points must exist	Database Object Name
`table`	Table to unlock	Must be in a database without transaction logging, and must be a table that you previously locked	Database Object Name

Usage

Restriction: The UNLOCK TABLE statement is not valid within a transaction.

You can lock a table if you own the table or if you have the Select privilege on the table, either from a direct grant to your user ID or from a grant to PUBLIC. You can only unlock a table that you locked. You cannot unlock a table that another process locked. Only one lock can apply to a table at a time.

You must specify the name or synonym of the table that you are unlocking. Do not specify the name of a view, or a synonym for a view.

To change the lock mode of a table in a database that was created without transaction logging, use the UNLOCK TABLE statement to unlock the table, then issue a new LOCK TABLE statement. The following example shows how to change the lock mode of a table in a database that was created without transaction logging:

LOCK TABLE items IN EXCLUSIVE MODE;
...
UNLOCK TABLE items; 
...
LOCK TABLE items IN SHARE MODE;

The UNLOCK TABLE statement fails if it is issued within a transaction. Table locks set within a transaction are released automatically when the transaction completes.

If you are using an ANSI-compliant database, do not issue an UNLOCK TABLE statement. The UNLOCK TABLE statement fails if it is issued within a transaction, and a transaction is always in effect in an ANSI-compliant database.