VARCHAR Constraints - Access Module

VARCHAR Constraints

By default, the Teradata OLE DB Access Module uses the maximum VARCHAR data type specification supported by Teradata Database: 64000 B. Data types like SQL Server “text” can return a length that greatly exceeds the 64000 B maximum. When selecting columns of this type, remember that:

Rows with a total length exceeding the maximum are not loaded; long string data are not truncated.

After the Teradata OLE DB Access Module returns all rows it can successfully return, in response to the next request for rows the access module returns an error message indicating the number of rows not loaded. This usually causes the job to fail.

When truncating long string data, use an SQL command to create the rowset to be loaded. When using the SQL command, specify the SUBSTRING function in the select‑item‑list of the SELECT command to truncate the data before it reaches the Teradata OLE DB Access Module.