Module 01 · Introducing NoSQL

Glossary: Working with Distributed Data术语表：分布式数据操作

Welcome! This alphabetized glossary contains many of the terms you'll find within this course. This comprehensive glossary also includes additional industry-recognized terms not used in course videos. These terms are important for you to recognize when working in the industry, participating in user groups, and participating in other certificate programs.
欢迎！这个按字母顺序排列的术语表包含了您在本课程中会发现的大量术语。这个全面的术语表还包括了课程视频中未使用的、行业认可的术语。这些术语对于您在行业内工作、参与用户组以及参与其他认证项目时都非常重要。

Term 术语	Definition 定义
ACID	This term is an acronym for Atomicity, Consistency, Isolation, and Durability, which is a set of properties that guarantee reliable processing of database transactions in traditional relational databases. 这个术语是 Atomicity, Consistency, Isolation, and Durability 的缩写，它是一组保证传统关系型数据库中数据库事务可靠处理的属性。
Atomic 原子	In the context of database transactions, atomic means that an operation is indivisible and either completed fully or is completely rolled back. It ensures that the database remains in a consistent state. 在数据库事务的上下文中，原子性意味着一个操作是不可分割的，要么完全完成，要么完全回滚。它确保数据库保持一致状态。
Availability 可用性	In the context of CAP, availability means that the distributed system remains operational and responsive, even in the presence of failures or network partitions. Availability is a fundamental aspect of distributed systems. 在 CAP 的上下文中，可用性意味着分布式系统即使在存在故障或网络分区的情况下也能保持运行和响应。可用性是分布式系统的一个基本方面。
BASE	An alternative to ACID. Stands for Basically Available, Soft state, Eventually consistent. BASE allows for greater system availability and scalability, sacrificing strict consistency in favor of performance. ACID 的替代方案。代表基本可用、软状态、最终一致性。BASE 允许更高的系统可用性和可扩展性，以性能为代价牺牲了严格的一致性。
Basically available 基本可用	A basically available system remains operational even in the presence of failures or faults. 一个基本可用的系统即使在存在故障或错误的情况下也能保持运行。
CAP	CAP is a theorem that highlights the trade-offs in distributed systems, including NoSQL databases. CAP theorem states that in the event of a network partition (P), a distributed system can choose to prioritize either consistency (C) or availability (A). Achieving both consistency and availability simultaneously during network partitions is challenging. CAP 是一个强调分布式系统（包括 NoSQL 数据库）中权衡的定理。CAP 定理指出，在网络分区（P）的情况下，分布式系统可以选择优先考虑一致性（C）或可用性（A）。在网络分区期间同时实现一致性和可用性是具有挑战性的。
Consistency 一致性	In the context of CAP, consistency refers to the guarantee that all nodes in a distributed system have the same data at the same time. 在 CAP 的背景下，一致性指的是保证分布式系统中的所有节点在同一时间拥有相同数据。
Consistent 一致性	The action of being consistent ensures that a database transaction transforms the database from one consistent state to another. 保持一致性的行为确保数据库事务将数据库从一个一致状态转换到另一个一致状态。
Denormalized 非规范化	Denormalization is a database design technique used in NoSQL databases (and sometimes in traditional relational databases) where redundant or duplicate data is intentionally introduced into one or more tables to improve query performance and reduce the need for complex joins. 反规范化是一种数据库设计技术，用于 NoSQL 数据库（有时也用于传统关系型数据库），通过有意在单个或多个表中引入冗余或重复数据来提高查询性能，并减少对复杂连接的需求。
Durable 持久性	Guarantees that once a transaction is committed, its changes are permanent and will survive any system failures. 确保一旦事务提交，其更改将永久保存，并能经受任何系统故障。
Eventually consistent 最终一致性	An eventually consistent system reaches a consistent state, where all nodes have the same data given that there are no new updates. 一个最终一致性系统达到一致状态，在没有新的更新时，所有节点都具有相同的数据。
Isolated 隔离	Isolation refers to the property that multiple transactions can run concurrently without affecting each other. 隔离是指多个事务可以并发运行而不相互影响的特性。
Joins 连接	Combining data from two or more database tables based on a related column between them. 基于它们之间相关列将两个或多个数据库表中的数据结合起来。
Normalized 标准化	A database design practice where data is organized to minimize redundancy and maintain data integrity by breaking it into separate tables and forming relationships between them. 一种数据库设计实践，通过将数据分解到不同的表中并建立它们之间的关系，以最小化冗余并维护数据完整性。
Partition tolerance 分区容错性	In the context of CAP, partition tolerance is the ability of a distributed system to continue functioning even when network partitions or communication failures occur. 在 CAP 理论中，分区容错性是指分布式系统在发生网络分区或通信故障时仍能继续运行的能力。
Replication 复制	Replication involves creating and maintaining copies of data on multiple nodes to ensure data availability, reduce data loss, fault tolerance (improve system resilience), and provide read scalability. 复制涉及在多个节点上创建和维护数据副本，以确保数据可用性、减少数据丢失、容错性（提高系统弹性）以及提供读扩展性。
Sharding 分片	Refers to the practice of partitioning a database into smaller, more manageable pieces called shards to distribute data across multiple servers. Sharding helps with horizontal scaling. 指将数据库划分为更小、更易于管理的片段，称为分片，以将数据分布在多个服务器上。分片有助于水平扩展。
Soft state 软状态	A soft state acknowledges that the system's state might be transiently inconsistent due to factors like network partitions or concurrent updates. And it's willing to accept a certain level of inconsistency or uncertainty in the data temporarily. 一种软状态承认由于网络分区或并发更新等因素，系统的状态可能会暂时不一致。并且它愿意暂时接受数据中一定程度的不一致性或不确定性。
Transactions 事务	Transactions are sequences of database operations (such as reading and writing data) that are treated as a single, indivisible unit. 事务是一系列数据库操作（如读取和写入数据），它们被视为一个单一、不可分割的单位。