Apache CouchDB vs Azure DocumentDB

Apache CouchDB is a free document database that stores named documents and lets applications read and update them through a RESTful HTTP API. Documents can contain fields and binary attachments without following a fixed schema. Its query engine supports views made with JavaScript map functions and optional reduce functions. Incremental replication synchronizes databases in both directions between peers, including after disconnections; the project describes this as useful for offline-first applications across servers, phones, and browsers. PouchDB can replicate with CouchDB from mobile devices and web browsers. A cluster can present one logical database across multiple servers or virtual machines for added capacity and high availability. CouchDB uses an append-only file design, and its documentation describes document updates as ACID and all-or-nothing. Security features include administrator accounts, basic and cookie authentication, reader access controls, and JavaScript validation of document updates. Replicas may retain conflicting revisions for manual or automated resolution. CouchDB is self-hosted on servers or virtual machines, as a single node or cluster, and is licensed under Apache License 2.0.

Azure DocumentDB is a document database for applications using BSON and JSON. It supports transactions and vector search, with a maximum document size of 16.0 MB. Deployment options include managed cloud and another deployment model; listed platforms are Linux, macOS, and Windows. The Free Tier is billed Free for the life of the cluster and includes 32 GB of storage and one free database server per subscription. Fixed M-series plans provide different node capacities: M10 starts with 1 vCore and 2 GiB of memory per node, while M300 lists 96 vCores and 384 GiB per node. Between those are configurations with varying memory and compute, including burstable vCores on M25. M200-Autoscale is billed hourly according to usage and offers up to 64 vCores and 256 GiB of memory. Prices for the listed paid tiers are displayed as $-, with actual amounts depending on region and currency. This gives prospective users concrete capacity specifications alongside the free cluster allowance.