Variable-length national character strings are represented as NCHAR VARYING(n), where n is the number of characters. As with NCHAR, n must not be considered as the byte size because one character is stored as more than one byte in some language character sets. If n is not specified, the maximum length is set to 536,870,911. When the length of a character string exceeds n, the exceeding characters are truncated if they are space characters, or processed as an error otherwise. When a character string shorter than n is stored, the trailing space is not filled with space characters. That is, only necessary parts are stored.
NCHAR VARYING(n), NATIONAL CHAR VARYING(n) and NATIONAL CHARACTER VARYING(n) can be used interchangeably.
If you specify N'Härder' as NCHAR VARYING(8), 'Härder' is stored (a 6-character string).
If you specify N'Härder' as NCHAR VARYING(6), 'Härder' is stored (a 6-character string).
If you specify 'pacesetter' as NCHAR(12), an error occurs (that is, if a non-national string is specified for an attribute declared as a national character string).