Changes

The [[Database Module#db:node-pre|db:node-pre]] and [[Database Module#db:node-id|db:node-id]] functions can be called to retrieve the ''pre'' and ''id'' values of a node, and [[Database Module#db:open-pre|db:open-pre]] and [[Database Module#db:open-id|db:open-id]] can be used to go back and retrieve the original node. By default, ''id'' lookups are expensive. If the [[Options#UPDINDEX{{Option|UPDINDEX]] option }} is turned on, an additional index will be maintained to speed up the process.