See how Atlas and Capella compare in the DBaaS performance report

MongoDB vs. Couchbase

Customers who switch from MongoDB to Couchbase – whether on prem or in the cloud – have consistent reasons for doing so. Primarily these complaints center around performance challenges when scaling out, trouble using a proprietary query language, extra work from integrating separate technology capabilities, and challenges with mobile deployments. These difficulties result in wasted time, architectural and operational challenges, and a higher total cost of ownership.

Challenge 1: An unfamiliar query language

MongoDB's proprietary query language is far more complex and less well known than SQL

See for yourself


MongoDB provides a query method, find(), to query a collection with simple filtering and projection. For more complex operations, users have to use the aggregation framework to join, process, and aggregate multiple documents to return the result.

The MongoDB query method and aggregation framework are both proprietary and procedural, with limited expressive power and poor performance.


Couchbase adopts open standards and extends the SQL query language to support JSON data.

Key benefits over MongoDB’s proprietary methods include:

  • Familiarity of SQL
  • Declarative
  • Expressive power
  • Global indexes
  • Tunable consistency

Challenge 2: Flexible, scale-agnostic architecture

MongoDB leaves data at risk because it’s inflexible and can’t adapt to modern workloads

Learn more about MongoDB’s architectural weaknesses


MongoDB’s performance suffers from primary-secondary replication, which causes idle nodes and low hardware utilization.

All MongoDB services share the same resources, making it impossible to isolate workloads.

Single-node and sharded environments require different development patterns and changes to the way your application functions.
This discourages the use of sharding by putting the burden on the application and operations teams to know their data and tune it differently for different access patterns.


Couchbase was designed as an all-primary, clustered, and replicated distributed database from day one – all nodes can read and write. All users benefit from clustering and rebalancing, which improves data safety.

Built-in capabilities for replication across data centers ensure that your data is always on across the globe.

Multi-dimensional scaling enables independent scaling of services and workload isolation, optimizing performance and costs.

With high performance at scale, application behavior is unchanged whether growing from a single dev node to 3 test nodes or to 20 production nodes in a cloud.

Challenge 3: Performance at scale

MongoDB performance rapidly degrades as the cluster size or number of users increases

See how Couchbase outperforms MongoDB on enterprise workloads


MongoDB's performance suffers from limited page cache capability, requiring third-party tools to achieve acceptable norms for an enterprise-scale database.

Another MongoDB disadvantage is that inefficient routing layers add complexity and latency to requests.

Also, rigid data and index partitioning limitations require slow cross-node, scatter-gather methods for some queries. This approach slows query performance, especially on enterprise clusters.


Couchbase has a tightly managed and fully integrated caching layer for both data and indexes and doesn’t need additional caching products for high performance and single-digit latency speeds.

Intelligent routing with direct application-to-node document lookup allows for efficient communications with single network hop access.

Global indexes allow your indexes to be partitioned independently of data, minimizing latency for important queries.

Challenge 4: Integrated enterprise functionality

MongoDB limits many features depending on deployment model or third-party requirements

Learn more about integrated Couchbase capabilities


MongoDB’s key disadvantage is that some of its most attractive capabilities are bolted on rather than tightly coupled to the core database. These bolt-ons include replication, sharding, limited full-text search and SQL-based analytics.

Because MongoDB uses a proprietary query language that's hard to learn (Figure 1), you must hire developers with specific platform experience in order to get lasting value. (Or else take a long time to get up to speed.)

Finally, sharded environments have functionality limitations. Stitch functions and mobile sync are available only through the hosted Atlas offering.


Couchbase has unified application and management APIs across document lookup, structured query, full-text search, analytics and triggers. This gives developers easy access to all functionality, including security and management capabilities.

Couchbase’s query language extends ANSI SQL, supports multi-document ACID transactions, while still supporting advanced relational syntax. (Figure 1)

All functionality is available across all deployment models: on premises, containers, and cloud.

Challenge 5: Mobile and edge computing

MongoDB Realm does not support custom embedded devices, peer-to-peer sync, or complex multi-tier edge architectures

Learn more about Couchbase vs. MongoDB Realm for mobile and edge computing

MongoDB Realm

MongoDB Realm only supports smartphones, desktops, and tablets, not custom embedded devices, limiting the use cases it can support. Additionally, Realm sync is cloud centric and relies on internet connectivity, which presents an unpredictable point of failure.

Its reliance on the MongoDB Atlas backend-as-a-service (BaaS) platform to support mobile data sync service means that you can’t deploy the solution on premises, in private data centers, or in distributed cloud environments.

This severely limits options for meeting high availability and responsiveness requirements, as your applications become dependent on an inherently unreliable internet connection.

Couchbase Mobile

Couchbase Mobile is a flexible platform that supports any device, including mobile, desktop, and custom embedded hardware. It also supports multi-tenant security models and complex edge-to-cloud architectures, including peer-to-peer as well as multi-tier cloud-to-edge topologies.

You can deploy anywhere you need to – fully managed on Couchbase Capella App Services, or self-managed on premises or any private or public cloud.

Couchbase is cloud native, so you can use cloud tools such as the Couchbase Autonomous Operator for Kubernetes to easily deploy and manage your servers on the cloud or at the edge.

Why enterprises choose Couchbase over MongoDB


Today’s viewers demand seamless experiences and constant innovation. Finding MongoDB difficult to use and scale, DirecTV chose Couchbase for unparalleled performance at scale, bidirectional cross datacenter replication to keep services available for viewers 24/7, and N1QL for powerful queries.

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Pushed to scale at a rate its MongoDB and Redis backend could no longer support, Viber switched its messaging platform to Couchbase. With Couchbase, Viber cut its servers by more than 50%, is robust enough to avoid downtime, and now supports close to a million operations per second and datasets with billions of records.

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Nuance, a speech recognition and imaging software company, had a monolithic all-Oracle environment that was expensive to scale and inflexible for varied data types. As it explored NoSQL, Nuance found MongoDB hard to manage. It chose Couchbase instead for easy, cost-effective performance at scale and bidirectional replication.

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Staples needed to better manage B2B catalogs using 1.6 billion rules applied in real time. Staples tried MongoDB, but its inability to scale easily and affordably led to canceled projects. Couchbase not only enabled Staples to simplify its catalog management using N1QL and JSON, but also improved database performance and reliability.

Learn more

Figure 1: Couchbase extends ANSI SQL to support the flexible schema of JSON

Couchbase N1QL

SELECT SUM(value * volume) AS val, symbol
FROM   db.stocks
WHERE  symbol IN ( "AAPL", "GOOG" ) AND value > 0
GROUP  BY symbol
ORDER  BY val DESC, symbol ASC
MongoDB™ Query

	 { "$match": {
	 	 "$and": [
	 	 	 {"symbol": {
	 	 	 	 "$in": [
	 	 	 { "value": {
	 	 	 "$gt": 0 }}]}},
	 { "$group": {
	 	 "_id": {
	 	 	 "symbol": "$symbol" },
	 	 "sum(value * volume)": {
	 	 	 "$sum": {
	 	 	 	 "$multiply": [
	 { "$project": {
	 	 "_id": 0,
	 	 "sum(value * volume)": "$sum(value * volume)",
	 	 "symbol": "$_id.symbol"}}
	 { "$sort": {
	 	 "sum(value * volume)": -1,
	 	 "symbol": 1 }}]})

Altoros Report

An Analysis of Database Query Languages in MySQL, Couchbase Server, and MongoDB

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Compare Capella database services

Compare Couchbase Capella™ with other cloud Database-as-a-Service providers like MongoDB’s™ Atlas cloud service and Amazon’s DynamoDB database service. Find out why Couchbase Capella is the best solution for you.