How Do Informix Products Use GLS Locales?

Supporting Non-ASCII Characters

Nondefault locales that support the UNIX default code set, ISO8859-1, include British English (en_gb.8859-1), French (fr_fr.8859-1), Spanish (es_es.8859-1), and German (de_de.8859-1).

Sending the Client Locale

If CLIENT_LOCALE is not set (and DBNLS is not set), the client sets it to the default locale. If DB_LOCALE is not set (and DBNLS is not set), the client does not send a DB_LOCALE value to the database server.

The client application sends the LC_* environment variables only if DBNLS is set. If DBNLS is set but the LC_* variables are not, the client sets the appropriate LC_* values, based on the LANG environment variable, and sends these LC_* values to the database server. The client application does not send the value of the LANG environment variable to the database server.

A Version 5.x ALS client application can send DBCODESET to a Version 7.2 database server; the database server converts the DBCODESET value to a valid locale name and uses it as DB_LOCALE. A Version 6.x ALS client application sends the CLIENT_LOCALE and DB_LOCALE environment variables.

If you do not set any of these environment variables, the client application does not send them to the database server, and the database server uses the end-user formats that the client locale defines.

What Is Code-Set Conversion?

It does not convert between words in different languages. For example, it does not convert from the English word yes to the French word oui. It only ensures that each character retains its meaning when it is processed or printed, regardless of how it is encoded.

For example, if the character â is passed to a target computer whose code set does not contain that character, the target computer can never process or print the character exactly.

This method maps each mismatched character to a unique character in the target code set so that the return mapping maps the original character back to itself. This method guarantees that a two-way conversion results in no loss of information; however, data that is converted just one way might prevent correct processing or printing on the target computer.

This method maps all mismatched characters to one character in the target code set that highlights mismatched characters. This method guarantees that a one-way conversion clearly shows the mismatched characters; however, a two-way conversion results in loss of information if mismatched characters are present.

This method maps each mismatched character to a character in the target code set that looks similar to the source character. (This method includes the mapping of one-character ligatures to their two-character equivalents and vice versa.) This method tries to make printing of mismatched data more accurate on the target computer, but it most likely confuses the processing of this data on the target computer.

When Is Code-Set Conversion Performed?

For example, the code for the character â (a-circumflex) in Windows Code Page 1252 (a common Microsoft code set) is hexadecimal 0xE2. In IBM Coded Character Set Identifier (CCSID) 437 (a common IBM UNIX code set), the code is hexadecimal 0x83. If the code for â on the client is sent unchanged to the IBM UNIX computer, it prints as the Greek character (gamma). This action occurs because the code for is hexadecimal 0xE2 on the IBM UNIX computer.

For example, the code sets ccdc and big5 are both internal representations of a subset of the Chinese language. However, these subsets consist of different numbers of Chinese characters.

Locating Message Files