Function mapping is a new database object you can use to specify a simple name for executing a function on a foreign server.
You use the new CREATE FUNCTION MAPPING statement to create a function mapping. Then, you can specify the function mapping in a SELECT statement FROM clause using the table operator syntax. You use the new OUT TABLE clause to specify the function output tables.
Benefits
- You can use a function mapping instead of referring to a long name such as foreign_function@foreign_server, arguments, or complex function execution methods.
- Users can invoke functions without having to specify the location where the function is executed.
SQL Changes
The function mapping feature adds the following new statements:
- CREATE FUNCTION MAPPING statement to create a function mapping.
- REPLACE FUNCTION MAPPING statement to change the function mapping definition.
- DROP FUNCTION MAPPING statement to drop an existing function mapping.
- SHOW FUNCTION MAPPING statement to show the function mapping definition, including SHOW IN XML.
The following statements are enhanced to support function mapping:
- Extended SELECT statement FROM clause for table operator function mapping execution and a new OUT TABLE clause to specify the function output tables.
- GRANT and REVOKE statement support for EXECUTE and DROP privileges on a function mapping.
- BEGIN LOGGING and END LOGGING statement support for function mapping objects.
Considerations
- Function mapping support is limited to functions executed on a foreign server using QueryGrid, such as Aster Engine analytics functions and other remote functions.
- If you use ARC to archive, restore, or copy function mapping objects, you must use ARCMAIN version 16.20.00.03 or later.
Additional Information
For more information, see:
- Teradata Vantage™ SQL Data Definition Language Syntax and Examples, B035-1144
- Teradata Vantage™ SQL Data Manipulation Language , B035-1146