Pouchdb vs RxDB: What are the differences?

Introduction

PouchDB and RxDB are two popular NoSQL databases used for web applications, but they have distinct features and functionalities that set them apart. In this article, we will explore the key differences between PouchDB and RxDB.

1. Data Replication: PouchDB is primarily designed for client-side storage, enabling seamless data replication with CouchDB or another PouchDB instance on the server. It utilizes the built-in sync capabilities to synchronize changes bidirectionally. On the other hand, RxDB, which stands for Reactive Database, builds upon PouchDB and provides additional features like real-time synchronization, event-based observables, and offline capabilities.

2. Querying and Indexing: PouchDB offers a powerful querying mechanism by using MapReduce functions. It allows you to create complex queries for retrieving data from the database. In contrast, RxDB introduces RxQuery, a way to perform queries using the ReactiveX pattern. It provides a fluent API to filter, sort, and modify queried data in a reactive manner.

3. Modeling and Schema: PouchDB does not enforce any schema or provide easy ways to define models. It allows dynamic insertion of any JSON data. On the other hand, RxDB focuses on structured data and supports schema definition using the "RxSchema" module. It enables you to define data models with strict validation, default values, and methods for data manipulation.

4. Change Handling: PouchDB handles replication conflicts by using conflict resolution algorithms based on document revision numbers. In contrast, RxDB employs a conflict resolution strategy called "last write wins." It keeps track of document versions and resolves conflicts by considering the latest modification.

5. Observables and Event Handling: PouchDB does not include built-in support for reactive programming and event-based observables. In contrast, RxDB integrates with the popular RxJS library, providing powerful observables and event handling capabilities. It allows you to reactively subscribe to database changes, query results, and perform various transformations on data streams.

6. Plugin Ecosystem: PouchDB has a rich plugin ecosystem, offering a wide range of additional functionalities and integrations. These plugins can extend PouchDB's capabilities, such as encryption, full-text search, geospatial indexing, and more. RxDB inherits PouchDB's plugin ecosystem, allowing you to leverage various plugins seamlessly.

In summary, PouchDB is focused on data replication and client-side storage, while RxDB builds upon PouchDB to provide additional features like real-time synchronization, reactive querying, schema enforcement, and event-based observables. RxDB is an excellent choice for applications requiring offline capabilities and reactive data streams.