15.00 - Query Bands and Load Utilities - Teradata Database

Teradata Database SQL Data Definition Language Detailed Topics

prodname
Teradata Database
vrm_release
15.00
category
Programming Reference
featnum
B035-1184-015K

Query Bands and Load Utilities

The term load utilities include utilities or applications that use the Teradata FastLoad, MultiLoad, and FastExport protocols such as the Teradata Parallel Transport Load, Update, and Export operator, the FastLoad, MultiLoad, and FastExport utilities, and the embedded JDBC versions of FastExport and FastLoad.

You can classify these utilities based on session query bands. Because a transaction query band is discarded when a transaction ends, you should set a session query band when you use query banding with the Archive/Recovery utility or the data loading utilities if the query band is to be applied to all statements in the utility script.

Client load utilities can set several optional reserved query band names to control throttling. Teradata Database receives information about the name of the utility and the size of the data through these reserved query band names.

For example, a client utility can set the UtilityDataSize query band by means of a script. This sizing information is then used by Teradata Database as an aid in determining the number of AMP sessions to use for the load job.

The expected values for UtilityDataSize are SMALL, MEDIUM, and LARGE. These values provide Teradata Database with a simple way to influence the selection of the number of sessions needed to process the load job. The intent is to select a reasonable number of sessions for the default. You can use session configuration rules to provide a more precise selection.

Note that the client utilities do not set the UtilityDataSize query band automatically. To make use of UtilityDataSize, you must specify it in a script like the one in the following example.

     .LOGTABLE Logtable002;
     .LOGON tdpx/user,pwd;
 
      SET QUERY_BAND='UtilityDataSize=LARGE;' UPDATE FOR SESSION; 
 
     .BEGIN IMPORT MLOAD TABLES Employee;
     ..........
     .END MLOAD;
     .LOGOFF;

Refer to “Reserved Query Band Names and Values” on page 867 for a list of reserved query band names and values for the Teradata Database load utilities and to the appropriate Teradata Tools and Utilities documentation for more information about client utilities.