I have regular error in log

28705:20150730:094921.917
[Z3005] query failed: [-1]
ORA-00600: internal error code, arguments: [kksgaItLvl_Setup: desc], [3], [3], [], [], [], [], [], [], [], [], [] 
[select * from
 (select clock,ns,value 
from history_uint 
where itemid=164359 
and clock<=1437536959 and clock>1434944959
 order by clock desc) where rownum<=1]

• Unix timestamp conversion:
  • 1437536959 22.07.2015 3:49:19
  • 1434944959 22.06.2015 3:49:19
• Error appers from history sync process
• Main reason of error is Oracle bug in 12.1 version

But I would to know if it possible:

1. What operation is originator of this sql query
2. Why clock range in sql query so big (1 month)