Principles Of Distributed Database Systems Exercise Solutions !!exclusive!! <iOS>

Official exercise solutions for Principles of Distributed Database Systems

3. Reason about ordering and visibility

• For concurrency/transactions: use happens-before (Lamport clocks) or vector clocks to argue about causality.
• For serializability: construct or reason about the conflict graph (precedence graph). Show cycles → not serializable; acyclic → serializable.
• For linearizability: map each operation to an atomic point in a global timeline respecting real-time order.

Partitioned: The join requires moving large data amounts between sites, often needing re-fragmentation for efficiency. 2. Distributed Transparency Partitioned : The join requires moving large data

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2. Distributed Query Processing: Semi-Join Reduction

A classic exercise is to optimize a distributed join between two relations stored at different sites using semi-joins. Partitioned : The join requires moving large data

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Vertical fragmentation groups attributes into fragments that minimize join cost while preserving reconstructability via join on key. Partitioned : The join requires moving large data