15.10 - Assigning the Default Client Character Set by HostId - Teradata Database

If clients connect to the Teradata Database system using multiple host connections, you can assign a default character set for each HostID, by adding entries to the DBC.HostsInfoV view.

The DBC.HostsInfoV displays default character set assignments by HostID. See “Assigning Default Client Character Sets in DBC.HostsInfoV” on page 58.

Example DBC.HostsInfoV

   SELECT * FROM DBC.HostsInfoV;

   *** Query completed. Nine rows found. 3 columns returned. 

   *** Time was 2.14 seconds.

   LogicalHostId HostName DefaultCharSet 

   ------------- -------- -----------------------------

             136 VM       SWEDISH_EBCDIC

             137 VM       German_EBCDIC

             138 VM       Spanish_EBCDIC

             139 VM       French_EBCDIC

             140 VM       Italian_EBCDIC

             141 VM       Norwegian_EBCDIC

             142 VM       EBCDIC037_0E

            1076 PC_LAN   LATIN1_0A

Explanation of Example DBC.HostsInfoV

Field	Data Type	Comment
LogicalHostId	SMALLINT	Identifies the client connection (mainframe or LAN) for which a default character set is being defined. This value must be the same as the identifier established for this connection by the hardware configuration data. For details on how to determine the value, see “Finding the LogicalHostId” on page 58.
HostName	VARCHAR(128)	An arbitrary, user-assigned name for this host, for example, Mainframe1, TokyoLAN, or RetailWebsite.
DefaultCharSet	VARCHAR(128)	The name of the session character set to be used by default when passing data to and from the clients in the host group. The value in this column may be: A permanently enabled client character set EDCDIC ASCII UTF8 UTF16 A client character set name from the CharSetName column in DBC.CharTranslationsV for which the Install Flag is set to Y.

To assign a default character set for a host group, you must know the LogicalHostID for the group. The LogicalHostId is a 16-bit value equal to the host number + the client CPU architecture number.

You can find:

All the LogicalHostIds for a database system using the Configuration utility LIST HOST command. The output is similar to:

HOSTs ARRAY

_______________________

HostNo 	    LogicalHostID         Type 	        Connected PE Range

______ 	    _____________         ____ 	        __________________

52 	        1076 	                 COP 		         16379-16383

821 	        821 	                  IBM 		         16377

829 	        829 	                  IBM 		         16378

For details, see Utilities

The LogicalHostId through which an individual client logs on to the database by querying the DBC.SessionInfoV view, for example:

SELECT hostno, logicalhostid, username FROM DBC.SESSIONINFOV;

The output is similar to:

 HostNo LogicalHostId UserName

 ------ ------------- --------

 1      2049          MRN01END

After determining the LogicalHostId of the host for which you want to specify a default character set, you can make the assignments in the DBC.HostsInfoV view.

1 Use an INSERT statement to add a row in the DBC.HostsInfoV view for each host, for example:

   INS INTO DBC.HostsInfoV (1076, 'PC_LAN', 'LATIN1_0A');

where:

Syntax Element	Description.
1076	LogicalHostId
'PC_LAN'	Host name
'LATIN1_0A'	Default character set

2 Perform a restart of the Teradata Database, using the tpareset utility, to activate the defaults.

IF the restart...	THEN...
successfully activates the default character sets	the character set name and identifier for each client system are sent to the appropriate TDP during startup.
encounters errors with a default character set	the system defaults to this host character set: EBCDIC for mainframe clients ASCII for all other clients

3 Go to /var/log/messages to check for errors associated with loading default character sets into DBC.HostsInfoV.

When the system attempts to validate the rows in DBC.HostsInfoV, if a character set in the view is not enabled, the system logs an error in the /var/adm/messages log, for example:

   3133: Default Character Set is invalid.

   On Fri Apr 18 10:51:05 2003 on NODE 001-01, VPROC 16383, partition 13, task disabrt

   Default Character Set name:  'Portuguese_EBCDIC             '

4 If the log contains any errors, correct the problems and re-run steps 2 and 3.