Naming rules in a Unicode environment

In a Unicode database, all identifiers are in multibyte UTF-8. Therefore, it is possible to use any UCS-2 character in identifiers where the use of a character in the extended character set (for example, an accented character, or a multibyte character) is allowed by the Db2® database system.

Clients can enter any character that is supported by their environment, and all the characters in the identifiers will be converted to UTF-8 by the database manager. Two points must be taken into account when specifying national language characters in identifiers for a Unicode database:

• Each non-ASCII character requires two to four bytes. Therefore, an n-byte identifier can only hold somewhere between n/4 and n characters, depending on the ratio of ASCII to non-ASCII characters. If you have only one or two non-ASCII (for example, accented) characters, the limit is closer to n characters, whereas for an identifier that is completely non-ASCII (for example, in Japanese), only n/4 to n/3 characters can be used.
• If identifiers are to be entered from different client environments, they should be defined using the common subset of characters available to those clients. For example, if a Unicode database is to be accessed from Latin-1, Arabic, and Japanese environments, all identifiers should realistically be limited to ASCII.