Relational Algebra Operator Tree

Asked Feb 14 '18 at 02:52

Active Feb 14 '18 at 02:59

Viewed 480 times

Context: All customer pairs (C1,C2) such that C1 likes some pizza that C2 does not like.

LikeDislike(cname, cname2):

Question: Find all customer pairs (C1,C2) such that C1 < C2 and they like exactly the same pizzas.

Answer:

I'm not sure about the right side of the operator tree. Why does the answer include LikeDislike? When they are asking about C1 & C2 liking exactly the same pizzas.

edited Feb 14 '18 at 02:59

asked Feb 14 '18 at 02:52

user8779054

What are $\pi \sigma \rho?$ You question seems to end in the middle. What comes after "Would be"? – saulspatz Feb 14 '18 at 02:57
I forgot to delete the "Would be", thanks for pointing it out. – user8779054 Feb 14 '18 at 03:00
Relational Algebra--> π: Projection, σ: Selection, ρ: Renaming – user8779054 Feb 14 '18 at 03:08

Relational Algebra Operator Tree

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