ORA-02070: database does not support in this context

Problem Description
I like to differentiate between columns of table HISTORY from two databases using database link as below and it resulted error ORA-02070.
SQL> select * from cols where table_name='HISTORY' minus select * from cols@tiger1.net where table_name='HISTORY';
select * from cols where table_name='HISTORY' minus select * from cols@tiger1.net where table_name='HISTORY'
*
ERROR at line 1:
ORA-02070: database TIGER1.NET does not support operator NLS_CHARSET_DECL_LEN
in this context

I found that the cols contain LONG column and hence result above error. If I only query long datatype data_default then same error return with different error message.

SQL> select data_default from cols minus select data_default from cols@tiger1.net;
select data_default from cols minus select data_default from cols@tiger1.net
*
ERROR at line 1:
ORA-02070: database does not support in this context

Experiment and cause of the Error
The reason behind the error is the long datatype of data_default column. Wheenever you go to access long datatype column of cols then above error returns. However for experiment I created LONG datatype column table but did not get above error. I conclude that only SYSTEM defined table/view/synonym throw above error and user defined table/view/synonym throw ORA-00997.

For experiment,
1)Create table t with only long column in both database and then try to use minus operation using database link.

SQL> create table t(a long);

Table created.

SQL> select * from t minus select * from t@tiger1.net;
select * from t minus select * from t@tiger1.net
*
ERROR at line 1:
ORA-00997: illegal use of LONG datatype
ORA-02063: preceding line from TIGER1.NET

So in order to avoid above error just don't do any operation over LONG column through database link.