Distributed database

Definition

A distributed database is a collection of data that is stored across multiple physical locations, which can be on different servers or networks. This setup allows for improved data access and reliability, as well as the ability to scale systems more efficiently. Distributed databases can be homogeneous, where all sites use the same DBMS, or heterogeneous, where different systems are used across the network.

5 Must Know Facts For Your Next Test

1. Distributed databases enhance data availability since they can operate even if some nodes are down, thus providing better fault tolerance.
2. They enable geographical distribution of data, allowing users from different locations to access information quickly and efficiently.
3. Data consistency in distributed databases can be challenging due to potential latency issues and network partitions, often requiring complex algorithms like two-phase commit for transactions.
4. Many modern applications, especially those relying on cloud technologies, use distributed databases to manage large volumes of data across multiple environments seamlessly.
5. Distributed databases can facilitate improved performance through load balancing, allowing queries to be processed in parallel across various nodes.

Review Questions

• How does a distributed database enhance data availability compared to a traditional centralized database?
  • A distributed database enhances data availability by allowing data to be stored across multiple physical locations. This means that even if one node fails, other nodes can still provide access to the data, ensuring minimal downtime. In contrast, a centralized database relies on a single point of storage, making it more vulnerable to outages and failures that can lead to complete unavailability of the system.
• Discuss the challenges associated with maintaining data consistency in a distributed database environment.
  • Maintaining data consistency in a distributed database environment is challenging due to factors such as network latency and the possibility of network partitions. When transactions occur across multiple nodes, ensuring that all copies of the data reflect the same information requires complex protocols like two-phase commit. Additionally, if different nodes update data simultaneously, resolving conflicts and ensuring that all users see consistent information becomes complicated.
• Evaluate the impact of using distributed databases on modern application development and scalability.
  • Using distributed databases significantly impacts modern application development by enabling scalability and flexibility. Developers can design applications that scale out horizontally, distributing workloads across multiple nodes to handle increased user demand effectively. This architecture allows for seamless growth as traffic rises without overloading a single system. Furthermore, the geographical distribution of data enhances user experience by reducing latency and providing faster access to information for users around the globe.

Related terms

Replication: The process of copying and maintaining database objects in multiple locations to ensure data availability and reliability.

Fragmentation: The method of dividing a database into smaller parts, called fragments, which can be distributed across different locations to improve performance and manageability.

Transparency: The characteristic of a distributed database that allows users to access data without being aware of its physical location or the underlying complexities of the system.