Storing double characters in an oracle table

[boxtoby]

I have a job which stores data in an oracle table and works fine with European data. However with double byte characters the job aborts with the error "ORA-01401: inserted value too large for column".

My question is when working with double byte characters is it necessary to double the size of the affected columns or is there something I can set which caters for this "behind the scenes"? I should also say that shorter double byte strings are written away fine, it's just those that are slightly too long for the column

My columns are set to NVarChar and NLS is on and set to the default charac ter set. Can I also ask what the difference is between NVarChar and extended unicode? I notice that they mutually exclusive.

Thanks in advance.

Bob.