Description of the illustration search_clause.eps

{ SEARCH
        { DEPTH FIRST BY c_alias [, c_alias]...
            [ ASC | DESC ]
            [ NULLS FIRST | NULLS LAST ]
         | BREADTH FIRST BY c_alias [, c_alias]...
            [ ASC | DESC ]
            [ NULLS FIRST | NULLS LAST ]
        }
        SET ordering_column
}