SQL Descriptor Fields - ODBC Driver for Teradata

Teradata Database Versions from V2R6.2 and up support improved meta data for parameters used in SQL requests and for columns in result sets. The improved meta data is collectively known as Extended Statement Information. ODBC Driver for Teradata uses the extended statement information if it is supported by the database, but the use of extended statement information in ODBC can also be explicitly disabled through a configuration option (Enable Extended Statement Information check box in the DSN setup dialog, and EnableExtendedStmtInfo in the odbc.ini file).

When extended statement information is available in ODBC Driver for Teradata, a conforming application should not experience any differences. The application can:

Discover that SQLDescribeParam is supported and start using it

Receive SQL_UNKNOWN_TYPE when calling SQLGetDescField for some parameters in certain SQL expressions where the database cannot determine the type

Find that some descriptor fields that were not set are now set or have different values

Discover that information about datetime types and intervals is now more precise

The different values of some of the descriptor fields in ODBC Driver for Teradata when extended statement information is available might affect applications that rely on the old behavior. If necessary, such applications can obtain the old behavior by disabling extended statement information in the ODBC configuration.

The following sections describe differences in the values of descriptor fields when extended statement information is available.