The ALTER FUNCTION statement provides an option that controls whether Teradata Database invokes the function directly or runs the function indirectly as a separate process.
The option applies to functions that were created without specifying the EXTERNAL SECURITY clause in the CREATE FUNCTION or REPLACE FUNCTION statement. Functions that specify the EXTERNAL SECURITY clause are executed using separate secure server processes.
| IF ALTER FUNCTION specifies … | THEN Teradata Database … |
|---|---|
| EXECUTE PROTECTED | runs the function indirectly as a separate process. If the function fails during execution, the transaction fails. |
| EXECUTE NOT PROTECTED | invokes the function directly. If you subsequently use REPLACE FUNCTION to replace the function, the execution mode reverts back to protected mode. |
Only an administrator, or someone with sufficient privileges, can use the ALTER FUNCTION statement.