Const
A join: its type, always written (LEFT_OUTER included), and its key columns paired by position, kept exactly as they are, even when they are empty or don't pair up (validation reports that).
LEFT_OUTER
A join: its type, always written (
LEFT_OUTERincluded), and its key columns paired by position, kept exactly as they are, even when they are empty or don't pair up (validation reports that).