Changes

==Effects==

In BaseX, all updates are performed on database nodes. Update operations thus never affect the original input file. You can, however, use the [[Commands#EXPORT|EXPORT]] command or the fn:put() function to create an updated XML file.

Moreover changes in your database are propagated back to the original input file if the database option <code>[[Options#WRITEBACK|WRITEBACK]]</code> is turned on. This option can also be activated on [[Startup Options#BaseX Standalone|command line]] via <code>-u</code>. Make sure you back up the original data before running your queries.

By default, index structures are discarded after an update