6.830/6.814: Database Systems
Spring 2021
We will continue our discussion of parallel and distributed query processing. You should read:

This paper discusses distributed transactions, addressing the problem of providing ACID-style semantics in a shared nothing environment.

As you read the paper, consider the following questions:

  1. How does the two phase commit (2PC) protocol work? What problem does it solve? What are the costs of using it?
  2. What is the significance of the Presumed Abort/Presumed Commit variants of 2PC? How do they reduce the overhead of 2PC? When should you choose one over the other?