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Teradata RDBMS forUNIX SQL Reference - NCR

NCR Teradata RDBMS forUNIX SQL Reference - NCR, 1997. - 913 p.
Download (direct link): teradataforunix1997.pdf
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Whether your character support will be International or Japanese is determined by the HashFuncDBC field in the RDBMS Control Record, which is set and changed through the RDBMS Control Utility, and only takes effect after a SysInit.

For more information on changing or viewing this field, refer to the Teradata RDBMS for UNIX Support Utilities Manual, “RDBMS Control Utility”, and “SysInit Utility”.

The RDBMS Control Record is also discussed in Chapter 14 of the Teradata RDBMS for UNIX Database Design and Administration Manual.

• International. When HashFuncDBC is International (the default) (select 1 - International, from SysInit), International Character support is enabled.

• Japanese. When HashFuncDBC is Kanji (select 2 - Kanji, from SysInit, Japanese Character support is enabled. To establish your site as a Japanese character site, refer to the section “Setting up Japanese Character Support”.

Teradata RDBMS for UNIX SQL Reference
International and Japanese Character Support

Overview

Caution:

The Sysinit utility must be used to register a change to the value of the HashFuncDBC field. On an existing configuration, this means all data must first be unloaded. If you are already running the Teradata RDBMS and you want to change the hashing algorithm, it is recommended that you contact your NCR field representative before proceeding. Refer to the Teradata RDBMS for UNIX Support Utilities Manual, for a description on how to use Sysinit.

Teradata RDBMS for UNIX SQL Reference G-5
International and Japanese Character Support

Defining Character Sets

External to Internal, Lowercase and Uppercase Translations

Defining Character Sets

Data characters are stored internally by Teradata as described in the appropriate section of the manual. The translation codes to convert standard characters to and from Teradata Extended ASCII and EBCDIC are provided in every Teradata configuration.

During data manipulation, the Teradata RDBMS performs the following translation functions:

• Characters received from a client system are translated into a form suitable for storage and processing on the Teradata RDBMS (external to internal).

• Characters returned to a client are translated into a form suitable

for storage, display, printing, and processing on that client (internal to external).

Each function requires one set of translation codes for lowercase letters and another for uppercase letters. Thus, four groups of hexadecimal translation codes are required for every character set, as follows:

• Lowercase external-to-internal

• Uppercase external-to-internal

• Lowercase internal-to-external

• Uppercase internal-to-external

The hexadecimal representations needed to translate a character set are inserted as one row in the DBC.Translation table via the DBC.CharTranslations view. The total number of rows that can be inserted into the table is unlimited. However, only six sets can be current at one time.

Each group occupies a column in the DBC.Translation table. Columns of DBC. CharTranslations, and an example of a completed row, are provided in the following sections.

To define your own character sets, adhere to the rules detailed in the next section, “User-Defined Character Set Restrictions”.

The Teradata internal (ANSI-standard) hexadecimal representation of each supported character is listed in Table G-1, and also in Appendix E, “ASCII Hexadecimal Translation Tables.”

G-6

Teradata RDBMS for UNIX SQL Reference
International and Japanese Character Support

Defining Character Sets

Creating and Implementing Character Sets

Creating and implementing an International or Japanese character set involves four major steps, as follows:

Step

Action

Define the external/internal and internal/external hexadecimal codes for both lowercase and uppercase translation for each character in the set, including diacritical and Katakana characters.

1

To define the character set, perform the following procedure.

Step Action
1 For each character set, define the following values: • A unique name of up to 30 bytes • A unique identifier (use a value in the range 65 to 126) • The install-flag value (Y or N); flag no more than six for Y (any number of rows can be inserted in the table, but only six will be installed and available at one time) • The four groups of translation codes Refer also to the following section “User-Defined Character Set Restrictions”.
2 If you want to use one or more alternative currency symbols, map the appropriate external value to the predefined value for each symbol. The value must be placed in your character set translation tables at the designated position. For example, your external code for a dollar sign must map to the internal code 0x24, so that the dollar sign can be used as a currency symbol. See also the section “Alternative Currency Symbols”.

2 Insert the codes using the DBC.CHARTranslations view. Each item in the character set is associated with a column in the DBC.CharTranslations view, and described in the section, “Columns in DBC. CharTranslations View”. An example of a BTEQ file that defines a Finnish/Swedish character set is given under the section titled “Example of Inserting the Swedish Character Set into DBC.CharTranslations”.
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