Lecture 12: Distributed Transactions

The podcast delves into distributed transactions, focusing on concurrency control and atomic commit as key implementation components. It explains how sharding data across multiple servers necessitates distributed transactions, using the example of a bank splitting customer data across servers. The discussion covers the ACID properties—atomicity, consistency, isolation, and durability—emphasizing isolation and its serializability definition. The host uses an example of transferring funds between bank accounts to illustrate transaction execution and potential conflicts. Two-phase locking, including pessimistic and optimistic concurrency control, is explored as a method to ensure serializability, highlighting the importance of holding locks until a transaction completes to prevent issues like phantom values from aborted transactions. The discussion also covers the two-phase commit protocol, including the roles of transaction coordinators and participants, and how it ensures atomicity against crashes and failures.