org.apache.derby.iapi.store.access.BackingStoreHashtable.spillToDisk(Unknown
This sounds like DERBY-2354: https://issues.apache.org/jira/browse/DERBY-2354 Unfortunately, there's not a fix for that problem yet. You can possibly avoid this problem by changing the memory parameters so that the backing store hash table does not try to spill to disk, but depending on the size of your database and the amount of memory you can give to Derby, that may or may not be successful. thanks, bryan
