4.9.2.96 UID function (extension)

UID returns an integer identifier for the user of the current transaction, as determined by the host operating system.

The value contained in this register is of INTEGER type. The host representation is of long integer type. SQL statements can refer to UID anywhere they can refer to an integer expression. For example,

INSERT INTO objects (owner_id, object_id)
           VALUES (UID, 1001) ;

SELECT *
    FROM objects
    WHERE owner_id = UID ;