Why NoSQL? - Couchbase
Why NoSQL?
The Shift to the Digital Economy is driving NoSQL
The business world is undergoing massive change as industry after industry shifts to the Digital
Economy. It’s an economy powered by the Internet and other 21st century technologies – the
cloud, mobile, social media, and big data. At the heart of every Digital Economy business are its
web, mobile, and Internet of Things (IoT) applications: They’re the primary way companies interact
with customers today, and how companies run more and more of their business. The experiences
that companies deliver via those apps largely determine how satisfied — and how loyal —
customers will be.
How are these applications different from legacy enterprise applications like ERP, HR and financial
accounting? Today’s web, mobile, and IoT applications share one or more (if not all) of the following characteristics. They need to:
Support large numbers of concurrent users (tens of thousands, perhaps millions)
Deliver highly responsive experiences to a globally distributed base of users
Be always available – no downtime
Handle semi- and unstructured data
Rapidly adapt to changing requirements with frequent updates and new features
Building and running these web, mobile, and IoT applications has created a new set of technology
requirements. The new enterprise technology architecture needs to be far more agile than ever
before, and requires an approach to real time data management that can accommodate unprecedented levels of scale, speed, and data variability. Relational databases are unable to meet these
new requirements, and enterprises are therefore turning to NoSQL database technology.
Consider just a few examples of Global 2000 enterprises that are deploying NoSQL for mission
critical applications that have been discussed in recent news reports:
Tesco, Europe’s #1 retailer, deploys NoSQL for ecommerce, product catalog, and other applications
Marriott is deploying NoSQL for its reservation system that books $38 billion annually
Gannett, the #1 U.S. newspaper publisher, uses NoSQL for its proprietary content
management system, Presto
GE is deploying NoSQL for its Predix platform to help manage the Industrial Internet
NoSQL was pioneered a decade ago by leading Internet companies – including Google, Amazon,
Facebook, and LinkedIn – to overcome limitations of relational databases like Oracle, and MySQL
for modern web applications. Once these early pioneers proved the advantages and efficacy of
NoSQL, adoption by enterprises started to unfold in three overlapping phases:
Grassroots Experimentation: In phase I (which started around 2010), enterprise developers
began experimenting with NoSQL on side projects and non-mission-critical applications. Their key
requirement was flexibility to support agile development of proofs of concept and small applications.
Mission Critical Deployments: In phase II (which began around 2013), enterprises started to
adopt NoSQL for mission critical applications. In this phase, the key requirements are performance, scalability, and availability to develop and / or migrate targeted services.
Broad Replatforming: In phase III (which is just starting in late 2015), both developers and
enterprises require a general purpose database for broad enterprise adoption to re-platform
all mission-critical applications and services for the Digital Economy. In this phase, NoSQL
database requirements include flexibility, performance, scalability, and availability as well as a
comprehensive query language and powerful indexing.
Five Trends Create New Technical Challenges that NoSQL Addresses
At a more granular level, enterprises are adopting NoSQL in order to address a new set of
technical challenges and requirements that are the result of five major trends:
1. More customers are going online
More and more customers are doing more and more online, whether at home, at work, or on the
go. They’re paying bills, making reservations, shopping for groceries – the list goes on and on –
and they’re doing it online, not at the local branch, travel agency, or grocery store.
Technical challenges from the shift to online include:
Scaling to support thousands if not millions of users
Meeting user experience requirements with consistent high performance
Maintaining availability 24 hours a day, 7 days a week
2. The Internet is connecting everything
It’s not just people going online and getting connected. Today, more and more “things” are connected to the Internet – the “Internet of Things” – and they’re both consuming and producing
data. They’re consumer things – appliances, watches, automobiles, and more. They’re industrial
things – airplane engines, wind turbines, oil rigs and pipelines, and more. They’re big. They’re
small. They’re local. They’re remote.
Technical challenges from the Internet of Things include:
Supporting many different (and often new) things, with different data structures
Supporting hardware and software updates that change the structure of data
Supporting continuous streams of real-time data
3. Big Data is getting bigger
Today, enterprises are leveraging big data to improve the efficiency and effectiveness of operations, applications, services, and more as a result of customers doing more and more online and
machines generating more and more data.
Technical challenges from Big Data include:
Storing semi-structured and unstructured data generated by customers
Storing different types of data, potentially from different sources, together
Storing data generated by thousands, if not millions, of customers and things
4. Applications are moving to the cloud
The ability to scale on demand and to operate at scale requires elastic, if not global, infrastructure, as enterprises shift to distributed software and commodity hardware for cost, flexibility, and
performance advantages. This has led to adoption of cloud infrastructure, whether public, private,
hybrid, virtualized, containerized, or bare-metal.
Technical challenges from moving to the cloud include:
Scaling on demand to support more customers and/or store more data
Operating applications on a global scale to serve customers worldwide
Minimizing infrastructure costs and achieving a faster time to market
5. The world has gone mobile
More and more customers are interacting via mobile platforms – whether it’s a smartphone, a tablet, a watch, or something else. And enterprises are not only extending applications and services
to mobile platforms, they’re evaluating “mobile first” and now, “offline first” solutions.
Technical challenges from the move to mobile include:
Creating “offline first” apps that don’t require a network connection
Synchronizing mobile data with remote databases in the cloud
Supporting multiple mobile platforms with a single backend
Why relational databases fall short
Enterprises have relied on relational databases like Oracle, SQL Server, DB2, MySQL and others for
decades. So why does relational technology fail to meet the requirements of today’s web, mobile,
and IoT applications?
Relational databases were born in the era of mainframes and business applications – long before
the Internet, the cloud, big data, mobile and now, the Digital Economy. In fact, the first commercial implementation was released by Oracle in 1979. These databases were engineered to run on a
single server – the bigger, the better. The only way to increase the capacity of these databases was
to upgrade the servers – processors, memory, and storage – to scale up.
NoSQL databases emerged as a result of the exponential growth of the Internet and the rise
of web applications. Google released the BigTable research in 2006, and Amazon released the
Dynamo research paper in 2007. These databases were engineered to meet a new generation of
enterprise requirements: The need to develop with agility and to operate at any scale.
Develop with Agility
To remain competitive in the Digital Economy, enterprises must innovate – and now they have
to do it faster than ever before. As this innovation centers on the development of modern web,
mobile, and IoT applications, developers have to deliver applications and services faster than ever
before. Speed is critical, but so is agility, since these applications evolve far more rapidly than legacy applications like ERP. Relational databases are a major roadblock to agility, since they do not
support agile development very well due to their fixed data model.
Flexibility for Faster Development
A core principle of agile development is adapting to evolving application requirements: when
the requirements change, the data model also changes. This is a problem for relational databases
because the data model is fixed and defined by a static schema. So in order to change the data
model, developers have to modify the schema, or worse, request a “schema change” from the
database administrators. This slows down or stops development, not only because it is a manual,
time-consuming process, but it also impacts other applications and services.
Figure 1: RDBMS – An explicit schema prevents the addition of new attributes on demand
By comparison, a NoSQL document database fully supports agile development, because it is schema-less and does not statically define how the data must be modeled. Instead, it defers to the applications and services, and thus to the developers as to how data should be modeled. With NoSQL,
the data model is defined by the application model. Applications and services model data as objects.
With a document database, applications and services simply read and write documents. They write
data by serializing an object to a JSON document, and read data by deserializing a JSON document
to an object. As a JSON document is self-describing, an external schema is unnecessary. So by modifying an object to add or remove attributes, a developer can change the data model without having
to change the database. This translates into a huge boost in developer productivity and agility.
Figure 2: JSON – The data model evolves as new attributes are added on demand.
Simplicity for Easier Development
Another advantage of a document database that enables faster innovation is the ability for
applications to directly read documents: There’s no need for an object-relational mapping layer
between the application model and the data.
Applications and services model data as objects (e.g. employee), multi-valued data as collections
(e.g., roles), and related data as nested objects or collections (e.g. manager). However, relational
databases model data as tables of rows and columns – related data as rows within different tables,
multi-valued data as rows within the same table. The problem with relational databases is that
data is read and written by disassembling, or “shredding,” and reassembling objects. This is the object-relational “impedance mismatch.” The workaround is object-relational mapping frameworks,
which are inefficient at best, problematic at worst.
As an example, consider an application for managing resumes. It interacts with resumes as an object, the user object. It contains an array for skills and a collection for positions. However, writing
a resume to a relational database requires the application to “shred” the user object.
Storing this resume would require the application to insert six rows into three tables:
Figure 3: RDBMS – Applications “shred” objects into rows of data stored in multiple tables.
Reading this profile would require the application to read six rows from three tables:
Figure 4: RMDBS – Queries return duplicate data, applications have to filter it out.
In contrast, a document-oriented NoSQL database reads and writes data formatted in JSON – which
is the de facto standard for consuming and producing data for web, mobile, and IoT applications. It
not only eliminates the object-relational impedance mismatch, it eliminates the overhead of ORM
frameworks and simplifies application development because objects are read and written without
“shredding” them – i.e., a single object can be read or written as a single document:
Big Data
Product Marketing
Technical Marketing
Red Hat
"lastName": "Johnson",
"skills": ["Big Data", "Java",
"experience": [
"role": "Technical Marketing",
"company": "Red Hat"
"role": "Product Marketing",
"company": "Couchbase"
Figure 5: JSON – Applications can store objects with nested data as single documents.
What about querying and SQL?
It’s important to remember that “NoSQL” stands for “not only SQL.” SQL is a mature query technology used by millions of developers. Virtually every programming language and framework, as
well as nearly all BI and reporting tools, support SQL. So it’s important that developers should be
able to leverage their SQL skills and tools when working with a NoSQL database.
Couchbase Server 4.0 introduced N1QL, a powerful query language that extends SQL to JSON, enabling developers to leverage both the power of SQL and the flexibility of JSON. It not only supports
standard SELECT / FROM / WHERE statements, it also supports aggregation (GROUP BY), sorting
(SORT BY), joins (LEFT OUTER / INNER), as well as querying nested arrays and collections. In addition, query performance can be improved with composite, partial, covering indexes, and more.
Operate at Any Scale
Databases that support web, mobile, and IoT applications must be able to operate at any scale.
While it is possible to scale a relational database like Oracle (using, for example, Oracle RAC), doing so is typically complex, expensive, and not fully reliable. With Oracle, for example, scaling out
using RAC technology requires numerous components and creates a single point of failure that
jeopardizes availability. By comparison, a NoSQL distributed database – designed with a scale-out
architecture and no single point of failure – provides compelling operational advantages.
Alternatives such as manual
sharding require custom
application logic, introducing unnecessary complexity,
and while some relational
databases can be deployed as
a cluster, they are still limited
to scaling up. Oracle RAC,
for example, relies on shared
storage (e.g. SAN). While
adding nodes will scale reads
to a point, scaling writes
and storage will ultimately
require bigger hardware. In
addition, the shared storage
is not only a performance
bottleneck, it’s a single point
of failure. Further, Oracle RAC
is complex, requiring Oracle
Grid Infrastructure / Clusterware and Oracle Automatic
Storage Management, and expensive – requiring high-end
interconnect for storage as
well as high-end interconnect
for Oracle Cache Fusion.
Elasticity for Performance at Scale
Applications and services have to support an ever increasing number of users and data – hundreds
to thousands to millions of users, and gigabytes to terabytes of operational data. At the same
time, they have to scale to maintain performance, and they have to do it efficiently.
The database has to be able to scale reads, writes, and storage.
This is a problem for relational databases that are limited to scaling up – i.e., adding more processors, memory, and storage to a single physical server. As a result, the ability to scale efficiently,
and on demand, is a challenge. It becomes increasingly expensive, because enterprises have to
purchase bigger and bigger servers to accommodate more users and more data. In addition, it can
result in downtime if the database has to be taken offline to perform hardware upgrades.
This leads to under- and over-provisioning. If the server turns about
to be too big, the excess capacity
is an unnecessary cost. If it turns
out to be too small, degraded
performance results in a poor user
Figure 6: RDBMS – The server is too
big or too small, leading to unnecessary
costs or poor performance.
A distributed NoSQL database,
however, leverages commodity
hardware to scale out – i.e., add
more resources simply by adding
more servers. The ability to scale
out enables enterprises to scale
more efficiently by (a) deploying
no more hardware than is required
to meet the current load,: (b)
leveraging less expensive hardware
and/or cloud infrastructure; and
(c) scaling on-demand and without
In addition to being able to scale
effective and efficiently, distributed NoSQL databases are easy to
install, configure, and scale. They
were engineered to distribute
reads, writes, and storage, and
they were engineered to operate at
any scale – including the management and monitoring of clusters
small and large.
Figure 7: NoSQL – Add commodity servers on demand so the
hardware resources matche the application load.
Availability for Always-on, Global Deployment
As more and more customer engagements take place online via web and mobile apps, availability
becomes a major, if not primary, concern. These mission-critical applications have to be available
24 hours a day, 7 days a week – no exceptions. Delivering 24x7 availability is a challenge for relational databases that are deployed to a single physical server or that rely on clustering with shared
storage. If deployed as a single server and it fails, or as a cluster and the shared storage fails, the
database becomes unavailable.
Figure 8: RMDBS – The failure of a server or storage device brings down the entire database.
In contrast to relational technology, a distributed, NoSQL database partitions and distributes data
to multiple database instances with no shared resources. In addition, the data can be replicated
to one or more instances for high availability (intercluster replication). While relational databases like Oracle require separate software for replication, for example, Oracle Active Data Guard,
NoSQL databases do not – it’s built in and it’s automatic. In addition, automatic failover ensures
that if a node fails, the database can continue to perform reads and writes by sending the requests
to a different node.
Figure 9: NoSQL – If an instance fails, the application can send requests to a different one.
As customer engagements move online, the need to be available in multiple countries and/or regions becomes critical. While deploying a database to multiple data centers increases availability
and helps with disaster recovery, it also has the benefit of increasing performance too, because all
reads and writes can be executed on the nearest data center, thereby reducing latency..
Ensuring global availability is difficult for relational databases where separate add-ons are required
– which increases complexity – or where replication between multiple data centers can only be
used for failover, because only one data center is active at a time. Oracle, for example, requires Oracle GoldenGate. When replicating between data centers, applications built on relational databases can experience performance degradation or find that the data centers are severely out of sync.
Figure 10: RDBMS – Requires separate software to replicate data to other data centers.
A distributed, NoSQL database includes built-in replication between data centers – no separate
software is required. In addition, some include both unidirectional and bidirectional replication
enabling full active-active deployments to multiple data centers – enabling the database to be deployed in multiple countries and/or regions and to provide local data access to local applications
and their users. This not only improves performance, it enables immediate failover via hardware
routers – applications don’t have to wait for the
database to discover the failure and perform its
own failover.
Figure 11: NoSQL – Replication between data centers is fully built-in, and
can be bi-directional.
NoSQL is a better fit for Digital Economy requirements
As enterprises shift to the Digital Economy – enabled by cloud, mobile, social media, and big data
technologies – developers and operations teams have to build and maintain web, mobile, and
Internet of Things (IoT) applications faster and faster, and at greater scale. NoSQL is increasingly
the preferred database technology to power today’s web, mobile, and IoT applications.
Hundreds of Global 2000 enterprises, along with tens of thousands smaller businesses and startups, have adopted NoSQL. For many, the use of NoSQL started with a cache, proof of concept or a
small application, then expanded to targeted mission-critical applications, and is now the foundation for all application development.
With NoSQL, enterprises are better able to both develop with agility and operate at any scale –
and to deliver the performance and availability required to meet the demands of Digital Economy
Next Steps — Additional Whitepapers
Moving from Relational to NoSQL: How to Get Started
This white paper will help you introduce NoSQL into your infrastructure by highlighting lessons
learned from enterprises that have successfully adopted NoSQL. We explore key considerations
and strategies for transitioning from a relational database to a NoSQL database, in particular, a
document database (Couchbase Server), with notes and hints for the transition from Oracle and
other relational databases. There will be times where NoSQL databases are not a replacement for,
but a complement to existing infrastructure.
We start with recommendations for identifying and selecting the right application. Next, we cover
strategies for modeling relational data as documents, how to access them within your application,
and how to migrate data from a relational database. Finally, we highlight the basics of operating a
NoSQL database in comparison to a relational database, and provide guidance on how to conduct
a successful NoSQL proof of concept.
NoSQL Database Evaluation Guide:
How Leading NoSQL Databases Compare Across the Eight Core Requirements
This guide defines and details the eight core requirements for an effective NoSQL database. Based
on those requirements, the guide articulates how databases do or do not meet those requirements, and points out what to look for and what to avoid. It begins with Data Access, because the
key requirement for Phase III applications in the Digital Economy is the ability to query data with
an expressive language that enables developers to query any type of data independent of how it is
About Couchbase
2440 West El Camino Real | Ste 600
Mountain View, California 94040
Couchbase delivers the world’s highest performing NoSQL distributed database platform. Developers around the world use the
Couchbase platform to build enterprise web, mobile, and IoT applications that support massive data volumes in real time. The
Couchbase platform includes Couchbase Server, Couchbase Lite - the first mobile NoSQL database, and Couchbase Sync Gateway. Couchbase is designed for global deployments, with configurable cross data center replication to increase data locality and
availability. All Couchbase products are open source projects. Couchbase customers include industry leaders like AOL, AT&T,
Bally’s, Beats Music, BSkyB, Cisco, Comcast, Concur, Disney, eBay, KDDI, Nordstorm, Neiman Marcus, Orbitz, PayPal, Rakuten /
Viber, Tencent, Verizon, Wells Fargo, Willis Group, as well as hundreds of other household names. Couchbase investors include
Accel Partners, Adams Street Partners, Ignition Partners, Mayfield Fund, North Bridge Venture Partners, and West Summit.
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