What is CouchDB?
Apache CouchDB is an open source NoSQL document database that stores data in JSON-based formats.
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What is CouchDB?

Apache CouchDB (link resides outside ibm.com) is an open source NoSQL document database that collects and stores data in JSON-based document formats. Unlike relational databases, CouchDB uses a schema-free data model, which simplifies record management across various computing devices, mobile phones, and web browsers.

CouchDB was introduced in 2005 and later became an Apache Software Foundation (link resides outside ibm.com) project in 2008. As an open source project, CouchDB is supported by an active community of developers who continuously improve the software with a focus on ease of use and embracing the web.

Why use CouchDB?

For most enterprises, deciding on which vendor to use when sourcing data management technology can be a challenge. Not only does proprietary software impose certain licensing restrictions on the use of the technology, but there are business continuity concerns when moving all of your enterprise data into a “one-size-fits-all” database management system (DBMS) with no visibility into its internal structure.

CouchDB is different. Unlike proprietary software that can risk “vendor lock-in,” CouchDB is open source, free to use, and easily integrates within your current data management infrastructure. Because you have more control over the software, you also have more flexibility when adapting it to the unique needs of your business. Whether requiring a general purpose document store, enabling efficient data synchronization, or adopting an “Offline First” mindset, CouchDB gives businesses the flexibility they need to create durable, reliable, and scalable infrastructures.

This video explains more about CouchDB and how it works:

Notable CouchDB features

The motivation behind CouchDB’s development can be defined with one word: relax. CouchDB comes with a suite of features designed to lower the effort of running resilient distributed system. Here are some key features of CouchDB and how it’s different from other NoSQL databases.

Replication. One of CouchDB’s defining features is bi-directional replication, which enables synchronization of data across multiple servers and devices via bi-directional replication. This replication enables enterprises to maximize systems availability, reduce data recovery times, geo-locate data closest to end users, and simplify backup processes.

In CouchDB, there is no distinction whether data is housed on one server or on multiple. Rather, CouchDB identifies document changes as they occur from any source and ensures all database copies remain synchronized with the most up-to-date information. This allows multiple database replicas to be self-contained and managed while still housing accurate, real-time information across multiple computing environments.

Views. CouchDB uses views as the primary tool for running queries and creating reports from stored document files. Views allow you to filter documents to find information relevant to a particular database process. This information can then be mapped according to your preferences and extracted in a specific order.

The beauty of CouchDB is the freedom you have with how information is presented. Because CouchDB views are built dynamically and don’t directly affect any underlying document stores, there is no limitation to how many different views of the same data you can run. These views are created inside of special design documents and are able to be replicated across multiple database instances like regular stored data.

Another great feature of CouchDB is the availability of Apache MapReduce to create powerful indexes that easily locate documents based on any value that lives in them. You can then use these indexes to establish relationships from one document to the next and make a variety of calculations based on those connections.

HTTP API. CouchDB uses a REST API to access the database from anywhere, with full CRUD (create, read, update, delete) operations flexibility. This simple and effective means of database connectivity makes CouchDB flexible, fast, and powerful to use while remaining highly accessible.

Built for offline. When you are scaling your database usability and accessibility, being able to build applications that work as well offline as they do online is essential. CouchDB enables applications to store collected data locally on mobile devices and browsers, then synchronizes that data once it is back online.

Efficient document storage. In CouchDB, documents are the primary units of data used in JSON, composed of various fields and attachments for easy storage. There is no limit to the text size or element count of each document, and data can be accessed and updated from multiple database sources and across globally distributed server-clusters.

Compatibility. CouchDB is extremely approachable and offers a variety of compatibility benefits when it is integrated with your current infrastructure. CouchDB was written in Erlang (a general-purpose, concurrent, garbage-collected programming language and runtime system) making it both reliable and easy to work with for developers.

Because of its open source capabilities, CouchDB is extremely flexible and can be installed and run on various operating systems and virtualization tools. It also compatible with PouchDB, a lightweight database designed to run in browser of mobile devices.

CouchDB benefits

CouchDB offers benefits to users and developers alike.

ScalabilityThe architectural design of CouchDB makes it extremely adaptable when partitioning databases and scaling data onto multiple nodes. CouchDB supports both horizontal partitioning and replication to create an easily managed solution for balancing both read and write loads during a database deployment.

CouchDB features a very durable and reliable storage engine that was built from the ground up for multicloud and multi-database infrastructures. As a NoSQL database, CouchDB is very customizable and opens the door to developing predictable and performance-driven applications regardless of your data volume or number of users.

No read locks. In most relational databases—where data is stored in tables—if you ever need to update or modify a table, the row of data being changed becomes locked to other users until the modification request is processed. This can create accessibility issues for clients and overall bottlenecks in your data management processes.

CouchDB uses MVCC (Multi-Version Concurrency Control) to manage access to databases concurrently. This means that regardless of current database loads, CouchDB can run at full speed and without restrictions to its users. Since documents in CouchDB are versioned and appended in real-time, database read requests will always see the most recently updated database snapshots, regardless of who accessed the document first.

Open source development. Because of its strong backing and support in the open source community, CouchDB maintains a strong, reliable foundation for enterprise database management. Developed over several years as a schema-less solution, CouchDB offers unparalleled flexibility that simply can’t be found in most proprietary database solutions.

Related solutions

IBM Cloudant

The data layer for hyperscale, resilient, globally available applications, based on open source Apache CouchDB.

Take the next step
Based on Apache CouchDB, IBM Cloudant is a fully managed, distributed database optimized for heavy workloads and fast-growing web and mobile apps. Available as an IBM Cloud service with a 99.99% SLA, Cloudant scales throughput and storage elastically, and its API and replication protocols are compatible with Apache CouchDB for hybrid or multicloud architectures. Learn more and try IBM Cloudant