Unlock the database record.

 Unlock DATABASE [/Qualifiers ...]
 If DATABASE is not specified, all open databases are unlocked. If the current record for this database has been modified, it is written back to the record stream before the unlock takes place. If an error occurs during this write-back operation (e.g. duplicate key, record not locked for write, etc.), an error is generated for this statement. The record remains current, but is now considered to be unchanged so that the next record operation will not attempt another write-back.
 A record that has been written back to the record stream due to a write-back is not necessarily physically on disk. Use the /FLUSH qualifier on the UPDATE or END_INSERT statement to ensure that the record is actually written to disk.