NLS_LENGTH_SEMANTICS=CHAR and column storage size

From: Laurenz Albe <invite_at_spam.to.invalid>
Date: 02 Nov 2005 15:31:47 GMT
Message-ID: <1130945506.504341@proxy.dienste.wien.at>

My company considers using UNICODE databases with NLS_LENGTH_SEMANTICS=CHAR to avoid problems inserting a value like 'Länge' into a CHAR(5) or VARCHAR2(5) column.

Now I am concerned about space requirements of such a database because I don't understand enough about the storage of such columns.

DATA_LENGTH for a CHAR(5) or VARCHAR2(5) column will be 20.

Does that mean that there will be 20 bytes reserved for this column in each row?
Is it possible that migrated databases might grow by a factor 4?
Is there documentation how such columns are stored in Oracle?

Thank you,
Laurenz Albe Received on Wed Nov 02 2005 - 09:31:47 CST