The routine modifiers tell the database server about attributes of the UDR. You specify routine modifiers in the WITH clause of the CREATE FUNCTION or CREATE PROCEDURE statement. The database server supports routine modifiers for C UDRs to perform the following tasks.
| Type of UDR | Routine Modifier | More Information |
|---|---|---|
| Iterator function | ITERATOR | Writing an Iterator Function |
| Negator function | NEGATOR | Creating Negator Functions |
| Selectivity function | SELFUNC, SELCONST | Writing Selectivity and Cost Functions |
| Cost function | COSTFUNC, PERCALL_COST | Writing Selectivity and Cost Functions |
| Parallelizable UDR | PARALLELIZABLE | Creating Parallelizable UDRs |
| Recursive UDR | STACK | Managing Stack Usage |
| Ill-behaved UDR | CLASS | Defining a User-Defined VP |
| UDR that handles SQL NULL values as arguments | HANDLESNULLS | Handling NULL Arguments |
| UDR that is not valid within an SQL statement | INTERNAL | None |