Chapter 15, Problem 7PE

Explanation of Solution

Pseudocode:

Pseudocode for an iterator that implements indexed nested-loop join is as follows:

IndexedNL::open()

begin

    outer.open();

    inner.open();

    done_r := false;

  if (outer.next () != false)

        move tuple from outer output buffer to t_r;

    else

        done_r := true;

end

IndexedNL::close()

begin

    outer.close();

    inner.close();

end

boolean IndexedNL::next()

begin

    while (!done_r)

    begin

        if(inner.next(t_r [JoinAttrs]) != false)

        begin

            move tuple from inner output buffer to t_s;

            compute relation of t_r an t_s and place it in output buffer;

            return true;

        end

        else

            if(outer...