ORA-01489 result of string concatenation is too long

[Queyon]

In Oracle 8.1.7.2, there is a table (TAB) with a column (COLUMN) of VARCHAR2(4000).
When try to "SELECT COLUMN FROM TAB;", it works fine, but,
when try to "SELECT '-' || COLUMN || '-' FROM TAB;", it returns the ORA-01489 error.

ORA-01489 result of string concatenation is too long
Cause: String concatenation result is more than the maximum size.
Action: Make sure that the result is less than the maximum size.

Could you tell me what's the maximum size limit? Is there any way to increase the limit? Or if I need this COLUMN to concate with other strings, how could I implement?
Any help will be appreciate.
Thanks.

Queyon

[Shestakov]

Probably u got "line size after variable substitution" limit in sqlplus = 3000 bytes.

Check:
select length('-' || COLUMN || '-') l from tab;