Locale information for the database

The database server must know how to interpret the data in any columns with the locale-specific data types, NCHAR and NVARCHAR.

To handle this locale-specific data correctly, the database server must know the localized order for the collation of the data and the code set of the data. In addition, the database server uses the code set of the database locale as the code set of the server-processing locale.

The database server might have to perform code-set conversion between the code sets of the server-processing locale and the server locale. For more information, see Perform code-set conversion.

The database server uses the following precedence to determine this database information:
  1. The locale that the database server uses to determine the database information for the server-processing locale depends on the state of the database to which the client application requests a connection, as follows:
    1. For a connection to an existing database, the database server uses the database information from the database locale that it obtains when it verifies the database locale. If the client application does not send DB_LOCALE, the database server uses the DB_LOCALE that is set on the server computer.
    2. For a new database, the database server uses the DB_LOCALE, which the client application has sent.
  2. The locale that the DB_LOCALE environment variable on the server computer indicates
  3. The default locale (U.S. English)

HCL OneDB™ uses the precedence of steps 1, 2, and 3 in the preceding list to obtain the database information for the server-processing locale. You are not required to set the other environment variables.

Tip: The precedence rules apply to how the database server determines both the COLLATION category and the CTYPE category of the server-processing locale. For more information about these locale categories, see Locale categories.

For more information about how the database server obtains these environment variables, see Send the client locale.

If the client application makes another request to open a database, the database server must reestablish the database information for the server-processing locale, as follows:
  1. Reverify the database locale by comparing the database locale in the database to be opened with the value of the DB_LOCALE environment variable from the client application.
  2. Reestablish the server-processing locale with the newly verified database locale (from the preceding step).

For example, suppose that your client application has DB_LOCALE set to en_us.8859-1 (U.S. English with the ISO8859-1 code set). The client application then opens a database with the U.S. English locale (en_us.8859-1), and the database server establishes a server-processing locale with en_us.8859-1 as the locale that defines the database information.

If the client application now closes the U.S. English database and opens another database, one with the French locale (fr_fr.8859-1), the database server must reestablish the server-processing locale. The database server sets the eighth character field of the SQLWARN array to W indicate that the two locales are different. The client application, however, might choose to use this connection because both these locales support the ISO8859-1 code set. If the client application opens a database with the Japanese SJIS locale (ja_jp.sjis) instead of one with a French locale, your client application would probably not continue with this connection because the locales are too different.