Exist XML: Recovery

> Is there a documentation out there for how to recover from corrupt db (not 
> recover from backup)? 

It depends on what kind of issues you have. If it's just index failures: 

* stop the database 
* run a consistency check via the emergency export tool 
(http://exist-db.org/backup.html#d8e750) 
* remove all .dbx, .lck and .log files except dom.dbx, 
collections.dbx, symbols.dbx; also remove the lucene index dir 
* restart the db 
* trigger a reindex 

If the consistency check reports errors in documents or the collection 
hierarchy, it will be better to do a full restore. 

Source:
http://exist.2174344.n4.nabble.com/Recover-from-corrupt-db-exist-1-4-td3692989.html