2 votes 2 votes Let R1, R2, . . ., Rn be a decomposition of schema U. Let u(U) be a relation, and the ri=∏Ri(U) the following holds true? A) u⊆ r1⋈r2⋈r3...⋈rn B) u= r1⋈r2⋈r3...⋈rn C) u⊇ r1⋈r2⋈r3...⋈rn D) None of these Please explain the question and the solution. MiNiPanda asked Nov 21, 2017 • edited Nov 21, 2017 by MiNiPanda MiNiPanda 567 views answer comment Share Follow See all 2 Comments See all 2 2 Comments reply Arjun commented Nov 21, 2017 reply Follow Share 7.17 here http://www.cs.ucla.edu/classes/fall04/cs143/solutions/ch7.pdf 0 votes 0 votes MiNiPanda commented Nov 21, 2017 i edited by MiNiPanda Nov 21, 2017 reply Follow Share Thank you @Arjun Sir for the link. I tried to understand that but I am stuck in the place where it has written that ri=∏Ri(U) implies that t[Ri]∈ri, 1≤i≤n. What exactly does ri represent? 0 votes 0 votes Please log in or register to add a comment.
