DROP SEMAPHORE statement

Drops a semaphore.

Syntax

DROP SEMAPHORE [ IF EXISTS ] [ owner.]semaphore-name

Parameters

owner
The owner of the semaphore. owner can also be specified using an indirect identifier (for example, `[@variable-name]`).
semaphore-name
The name of the semaphore. semaphore-name can also be specified using an indirect identifier (for example, `[@variable-name]`).
IF EXISTS clause
Use this clause to drop a semaphore only if it exists. If a semaphore does not exist and this clause is specified, then nothing happens and no error is returned.

Remarks

An error is returned to any connection that is waiting to decrement the semaphore.

Privileges

You must have the DROP ANY MUTEX SEMAPHORE or DROP ANY OBJECT system privilege, or be the owner of the semaphore. For a temporary semaphore, you must be the connection that created the mutex.

Side effects

Automatic commit, but only for permanent semaphores.

Standards

ANSI/ISO SQL Standard
Not in the standard.

Example

The following statement drops a semaphore called license_counter:

DROP SEMAPHORE license_counter;