Changes

|Opens the database {{Code|$db}} and returns the node with the specified {{Code|$pre}} value.<br />The ''pre'' value provides access to a database node in constant time. It is not stored in the database. Instead, but it is implicitly given by the order in which the XML nodes are visited by a SAX parser. As a result, it will change whenever a node with a smaller ''transientpre'', i.e., it may change when values is added to or deleted from a database updates are performed.