Principles Of Distributed Database Systems Exercise Solutions 💯 Verified Source

Relations R1 (Site1, 100 tuples), R2 (Site2, 200 tuples), R3 (Site3, 50 tuples). Join graph: R1⋈R2 (cardinality 400), R2⋈R3 (cardinality 150), R1⋈R3 (cardinality 2000). Find optimal join order minimizing transmission cost. Assume cost = cardinality of intermediate result.

A distributed transaction T1: read(A) , write(B) , read(C) ; T2: write(A) , read(B) , write(C) . Data items A, B, C reside on different sites. Centralized lock manager vs. distributed lock manager. Explain how a deadlock could occur and one detection method. Relations R1 (Site1, 100 tuples), R2 (Site2, 200

The solutions guide reinforces several critical technical domains: Relations R1 (Site1

Every tuple belongs to at least one fragment? No — an employee in Sales but located in India is lost. So a default fragment or a Other fragment is needed. R2⋈R3 (cardinality 150)