Routine modifiers
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 to perform the following tasks.
| Type of UDR | Routine modifier | More information |
|---|---|---|
| Iterator function | ITERATOR | Write an iterator function |
| Negator function | NEGATOR | implementing a negator function with a C user-defined function |
| Selectivity function | SELFUNC, SELCONST | Write selectivity and cost functions |
| Cost function | COSTFUNC, PERCALL_COST | Write selectivity and cost functions |
| Parallelizable UDR | PARALLELIZABLE | Creating parallelizable UDRs |
| Recursive UDR | STACK | Manage stack usage |
| Ill-behaved UDR | CLASS | Define 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 |