National Language Support (NLS) questions.

From: Yuri Korostyshevski <ykoros_at_dowjones.net>
Date: 1997/09/29
Message-ID: <34302940.CA9A86AC@dowjones.net>#1/1

Hi everyone,

I am trying to understand what exactly I can or cannot do with Oracle NLS.
I would welcome an opportunity to discuss the following with someone who

has used Oracle's NLS extensively.

This excerpt comes from the Oracle Server Reference manual:

---

Specifying Character Sets

...
When a client application operates with a terminal that uses a different character set, then the client application's characters must be converted to the database character set, and vice versa. This conversion is performed automatically, and is transparent to the client application. The character set used by the client application is defined by the NLS_LANG parameter.

Character Set Conversion

Where a character exists in both source and destination character sets, conversion presents no problem. However, data conversion has to accommodate characters that do not exist in the destination character set. In such cases, replacement characters are used. The source character is replaced by a character that does exist in the destination character set.

Replacement characters may be defined for specific characters as part of a character set definition. Where a specific replacement character is not defined, a default replacement character is used. To avoid the use of replacement characters when converting from client to database character set, the latter should be a superset
(or equivalent) of all the client character sets.

---

I am interested in the case where there is a need for conversion between character sets with little or none common characters.
(e.g. Bulgarian and Chinese)

The questions I have are:
Is it possible to define replacement characters between ANY two character sets?
Where and how do I define the replacement characters? Where and when the conversion takes place, and exactly which parameters govern it?

Any help, especially from those who have created multi-lingual database applications, would be much appreciated.

Yuri Korostyshevskiy / Oracle DBA - Consultant Received on Mon Sep 29 1997 - 00:00:00 CDT