SQL
Examples
Invoke the 'duckdb_functions' table function:  
```sql
CALL duckdb_functions();
```  
Invoke the 'pragma_table_info' table function:  
```sql
CALL pragma_table_info('pg_am');
```  
Select only the functions where the name starts with `ST_`:  
```sql
SELECT function_name, parameters, parameter_types, return_type
FROM duckdb_functions()
WHERE function_name LIKE 'ST_%';
```