VARCHAR2 or NVARCHAR2

 Hi All,

The question comes from one review session of physical data model  in our database team. We usually use NVARACHAR2 to hold the strings which may constain special symbols such as copyright and it really works for most of cases.

In a short, we usually use VARCHAR2 for all string columns. But if business team says it may contain special symbols, we change the field to NVARCHAR2.

My question is why we can't use NVARCHAR2 for every column as we use VARCHAR2?

I don't know this design is correct or not. But I haven't really seen this kind of design that use NVARCHAR2 everywhere before.