If there are ties report all of them rename r1 to

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: B := ρA1(A)⋈A1.price < A2.priceρA2(A) C := B - (ρB1(B)⋈B1.price < B2.priceρB2(B)). C is the final answer. 4. Report the name of all customers who have bid at least three times on one listing. A := б !!.!"# ! !!.!"# ! !!.!"# (ρB1(Bid)×ρB2(Bid)×ρB3(Bid)) ∧ !!.!"#$% ! !!.!"#$% ! !!.!"#$% ∧ !!.!"# ! !!.!"# ! !!.!"# B := ∏!"#$ (A⋈A.B1.CID = Customer.CID Customer). B is the final answer. 5. A rating is usually not trustworthy if the customer who gave...
View Full Document

Ask a homework question - tutors are online