Distributed Database Question Bank with Answers 16

Distributed  and parallel database questions and answers for University exams

Question:

What is the goal of data allocation process when designing a distributed database? Discuss different criteria for “optimal” data allocation.

Answer:

• Reliability – more copies available in case of site crashes

• Increased performance for read-only queries

• Optimality may be defined in two ways: minimal cost and maximized performance.

• Minimal cost – cost of storing and querying a fragment at a site, cost of updating a fragment at all sites, cost of data communication

• Maximized performance – minimize query response time, maximize system throughput

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