{ function_name [ ( parameter_name [ [,] parameter_name ]... ) ]
| NULL
| numeric_literal
| [ schema_name . ] { table_name | view_name } . *
| [ [ schema_name . ] { table_name | view_name } . ] column_name
| sequence_name . { CURRVAL | NEXTVAL }
| subquery
| 'text'
} 
[ [ AS ] alias]