In page 136 of The Firebird Book Second Edition one can read:

"NCHAR VARYING(n),..., is a specialized implementation of VARCHAR(n) that is pre-defined with ISO8859_1 as its character set attribute"

I wonder if being a "specialized implementation" would give me any performance gain.

If not, what are the advantages of using nchar varying besides getting ISO8859_1 char set predefined ?

Thank you for your attention.

Obs.: English is not my native language so please accept my apologies for any eventual mistakes.