You can use a Teradata object as a source in a mapping or mapping task. When you configure a Teradata task, you define properties that determine how the Secure Agent extracts data from Teradata sources.
When you use Teradata source objects, you can select a single Teradata source object or multiple source objects. When you configure the advanced source properties, you configure properties specific to Teradata.
You can configure tracing levels, spool modes, and query band expressions when you use Teradata sources to read data from Teradata.
Tracing Levels
You can specify the tracing level for the driver, or for activities related to the Teradata PT infrastructure. Tracing determines the type of diagnostic messages that the system operator sends to the log file. You can specify the absolute path with the trace file name in the advanced source properties.
Tracing helps in providing detailed information in the log file that aids in problem tracking and diagnosis.
You can specify the following tracing functions at the driver or Teradata PT infrastructure level for Teradata PT API:
TD_OFF
Teradata PT API disables the tracing. Default is TD_OFF.
TD_OPER
Teradata PT API enables tracing for driver-specific activities for Teradata.
TD_OPER_CLI
Teradata PT API enables tracing for activites involving CLIv2.
TD_OPER_NOTIFY
Teradata PT API enables tracing for activities involving the Notify feature.
TD_OPER_OPCOMMON
Teradata PT API enables tracing for activities involving the operator common library.
TD_OPER_ALL
Teradata PT API enables all driver-level tracing.
Spool Modes
You can configure a task so that Teradata PT API uses one of the spool modes to extract data from Teradata. By default, Teradata PT API spools data while extracting data from Teradata. For information about the spool modes and their uses, see the Teradata documentation.
You can configure the following source properties for Spool Mode that Teradata PT API uses to extract data from Teradata:
Spool
Teradata PT API spools data while extracting data from Teradata. Data is stored in a buffer and then extracted.
NoSpool
Teradata PT API does not spool data while extracting data from Teradata. The NoSpool mode extracts data quickly without reading the data into a spool file before extracting data. If the database does not support the NoSpool option, Teradata PT API uses the Spool option.
NoSpoolOnly
Teradata PT API does not spool while extracting data from Teradata. If the database does not support NoSpool, the task fails with an error.
SQL Override Query
When you configure a mapping, you can specify an SQL statement to override the default query used to read data from the Teradata source.
Specify the SQL override query in the source properties of the mapping. In the SQL override query, you can specify the columns that you want to use from the source database.
For example, use the following SQL override query to extract employee records, matching rows by employee location, from the Teradata source:
select EMPID, EMPNAME, AGE, DOB, DEPTID, LOCATION, DESIGNATION, SALARY from employee where CITY='San Jose'
When you run the mapping, the Secure Agent extracts specific employee records belonging to San Jose based on the where clause defined in the SQL override query.
You must ensure that the number of columns, order of columns, and the data type you specify in the query matches with the Teradata source object.