Why sql select 'Hello'||'world012345678' from dual; cause error?

Question

I have problem and your help to solve it would be very much appreciated.
Can anybody tell why the result is so different for the following two sql-sentence in SQL/PLus?
sql>select 'Hello'||'world012345678' from dual;
sql>select 'Hello'||'world0123456789' from dual;
sql>select 'Hello'||'world012345678' from dual;
Result:
select 'Hello'||'world012345678' from dual
ERROR at line 1:
ORA-00600: internal error code, arguments: [17182], [158346180], [], [], [],
sql>select 'Hello'||'world0123456789' from dual;
Helloworld0123456789
I found that if the length of one string equals 14, then the sql will failed as the first sentence.

Answer 1

If you need to check the validity of DUAL then you have:
Select count(1) from DUAL ;
NOT
Select * from DUAL;
If you find more than 1, then
delete from dual;
insert into dual values ('x') ;
commit;
Then, try you offending query.