Pathkeys clarification on A3

[Muhammad Qureshi]

Assignment instructions state to not create new Pathkeys. Did it mean to
say don't create new PathKeyItems? I'm assuming Pathkeys are lists of
lists of PathKeyItems.

[Ken Salem]

Assignment instructions state to not create new Pathkeys. Did it mean to say don't create new PathKeyItems? I'm assuming Pathkeys are lists of lists
of PathKeyItems.

For example, consider this:

((d.dno, e.dno, m.dno), (e1.eno, m.eno))

The PathKeyItems are things like d.dno.
The Pathkeys that the assignment is referring to are, in this example:
(d.dno, e.dno, m.dno)
and
(e1.eno, m.eno)

The possible Pathkeys for a particular query are determined
when the query is parsed and analyzed. Lists of PathKeys,
like this:

((d.dno, e.dno, m.dno), (e1.eno, m.eno))

just reference those pre-determined PathKeys.

You should also just referenced the pre-determined PathKeys.
Don't try to create any new ones.

-KMS