by Ken Task.
Ran into this once when attempting to restore a version 1.9 course to a 2.x. Are you restoring a 1.9 backup?
The purpose of the mdl_resource_old, according to comments in the DB, is:
backup of all old resource instances from 1.9
Am looking at the DB for a Moodle 2.7.5+ (Build: 20150212)
It does exist but contains no records.
Not sure that this is accurate:
Potential coding error - existing temptables found when disposing database.
When the session with DB is ended temp tables would automatically be 'cleaned up' ... or so I've read in MySQL docs somewhere.
Is there anything residual in moodledata/temp/backup/ when restore attempt fails?
'spirit of sharing', Ken