Teradata provides functions that you can use for UDF development. For example, use the FNC_DbsInfo function to get session information related to the current execution of a UDF.
The following table shows categories of library functions that Teradata provides.
| Category | Use |
|---|---|
| Aggregate Intermediate Storage | Allocates the intermediate storage you need for accumulating summary information in an aggregate function |
| ARRAY Data Type Interface | Enable a UDF to access and set the values of the elements in an ARRAY data type |
| Global Information | Returns session information about the current execution of a UDF |
| Lob Access | Enable a UDF to use a locator to access the contents of a referenced object and to append data to a LOB object |
| Period Data Type Interface | Enable a UDF to access and set the value of a Period data type |
| Query Band Access | Return query band name-value pairs that have been set on a session, transaction, or profile to identify the originating source of queries and help manage task priorities and track system use |
| String Argument and Result Processing | Useful for UDFs that are used for the algorithmic compression and decompression of table columns |
| Table Function Processing | Required to implement table functions |
| TD_ANYTYPE Parameter Access | Enable a UDF to retrieve information about TD_ANYTYPE input and output parameters |
| Trace | Let you get trace output for debugging purposes during UDF development |
| UDT Interface | Enable a UDF to access and set the value of a distinct UDT or attribute values of a structured UDT |
For a list of all available functions and their descriptions, see C Library Functions.