CS712 Distributed Database Management Systems

CS712: Distributed Database Management Systems

CS712 Distributed Database Management Systems (DDBMS) is an advanced database course that addresses the challenges and solutions for managing data that is not stored on a single, centralized server. Instead, it explores systems where data is distributed across multiple computers (called nodes), connected by a network. This approach is essential for modern large-scale applications (like Google, Amazon, and Facebook) that need high availability, scalability, and fault tolerance.

This course builds on the foundation of a traditional DBMS (like CS403) and introduces a new set of complex problems. How do you execute a query that needs data from multiple sites? How do you ensure data remains consistent (e.g., ACID properties) when an update requires changing data on two different machines, and one of them might fail? How do you handle network partitions? The course covers the principles, architectures, and algorithms that make DDBMS possible.

Key Topics Covered:

• DDBMS Architecture: Understanding different architectures, such as shared-nothing, shared-memory, and shared-disk. This includes concepts of data fragmentation (splitting tables), replication (copying data for availability), and allocation (deciding where to store fragments/replicas).
• Distributed Query Processing: The complex process of optimizing and executing queries that span multiple nodes. This involves minimizing data transfer over the network, which is often the main bottleneck.
• Distributed Transaction Management: This is a core challenge. We will study how to maintain ACID properties in a distributed environment.
  • Concurrency Control: Extending locking protocols (like 2PL) to a distributed setting.
  • Commit Protocols: The famous Two-Phase Commit (2PC) protocol, which is used to ensure that a transaction is either committed on all participating nodes or aborted on all of them (atomicity).
• Data Replication and Consistency: Exploring the trade-offs between consistency, availability, and partition tolerance (the CAP Theorem). This includes primary-copy replication, multi-master replication, and the concept of eventual consistency.
• Modern Distributed Data Stores: An introduction to NoSQL databases (e.g., key-value stores, document stores) and "NewSQL" systems that are designed for web-scale distributed workloads and often relax traditional ACID guarantees for better performance and availability.

Course Objectives:

1. Understand the core principles and architectures of distributed database systems.
2. Design schemas for distributed databases, making decisions about fragmentation and replication.
3. Analyze the algorithms for distributed query processing and optimization.
4. Master the concepts of distributed transaction management, especially the Two-Phase Commit protocol.
5. Appreciate the challenges of consistency and availability (CAP Theorem) in modern data stores.

CS712 is a critical course for students interested in large-scale systems, cloud computing, data engineering, and backend development. It provides the foundational knowledge for building the robust, highly-available data systems that power the modern internet.