"Big Data" describes data sets so large and complex they are impractical to manage with traditional software tools. Big Data relates to data creation, storage, retrieval and analysis that is remarkable in terms of volume, velocity, and variety.
Volume. A typical PC might have had 10 gigabytes of storage in 2000. Today, Facebook ingests 500 terabytes of new data every day; a Boeing 737 will generate 240 terabytes of flight data during a single flight across the US; smart phones are proliferating, entailing massive increases in data created and consumed; sensors embedded into everyday objects will soon result in billions of new, constantly-updated data feeds containing environmental, location, and other information, including video.   
Velocity. Clickstreams and ad impressions capture user behavior at millions of events per second; high-frequency stock trading algorithms reflect market changes within microseconds; machine to machine processes exchange data between billions of devices; infrastructure and sensors generate massive log data in real-time; on-line gaming systems support millions of concurrent users, each producing multiple inputs per second.
Variety. Big Data data isn't just numbers, dates, and strings. Big Data is also geospatial data, 3D data, audio and video, and unstructured text, including log files and social media.
Traditional database systems were designed to address smaller volumes of structured data, or fewer updates, or a predictable, consistent data structure. Furthermore, traditional database systems were designed to operate on a single server, making increased capacity expensive and finite. As applications have evolved to serve large volumes of users, and as application development practices have become agile, the traditional use of the relational database has become a liability for many companies rather than an enabling factor in their business. Big Data for business and Big Data analytics have necessitated the creation of a variety of new technologies and architectures to allow companies to create new products and services.
Big Data: Operational and Analytical
The Big Data landscape is dominated by two classes of technology: systems that provide operational capabilities for real-time, interactive workloads where data is primarily captured; and systems that provide analytical capabilities for retrospective, complex analysis that may touch most or all of the data. These classes of technology are complementary and frequently deployed together to deal with Big Data for the enterprise.
Operational and analytical workloads for Big Data present opposing requirements and systems have evolved to address their particular demands separately and in very different ways. Each has driven the creation of new technology architectures. NoSQL systems focus on servicing highly concurrent requests while exhibiting low-latency for responses operating on highly selective access criteria. Analytical systems, on the other hand, tend to focus on high-throughput where queries can be very complex and touch most if not all of the data in the system at any time. Both systems tend to operate over many servers operating in a cluster, managing tens or hundreds of terabytes of data across billions of records.
For operational Big Data workloads, NoSQL Big Data systems such as document databases have emerged to address a broad set of applications, and other architectures, such as key-value stores, column family stores, and graph databases are optimized for more specific applications. NoSQL technologies, which were developed to address the shortcomings of relational databases in the modern computing environment, are faster, and scale much more quickly and inexpensively than relational databases. Critically, NoSQL Big Data systems are designed to take advantage of new cloud computing architectures that have emerged over the past decade to allow massive computations to be run inexpensively and efficiently. This makes operational Big Data workloads much easier to manage, and cheaper and faster to implement, which means that Big Data for the enterprise can create more business value at lower cost.
Analytical Big Data workloads, on the other hand, tend to be addressed by MPP database systems and MapReduce. These technologies are also a reaction to the limitations of traditional relational databases and their lack of ability to scale beyond the resources of a single server. Furthermore, MapReduce provides a new method of analyzing data that is complementary to the capabilities provided by SQL.
Operational and analytical Big Data systems are naturally complementary. One way to compare these two classes of systems is by examining a few of their core characteristics:
|Latency||10 ms - 100 ms||1 min - 100 min|
|Concurrency||1000 - 100,000||1 - 10|
|Access Pattern||Writes and Reads||Reads|
|End User||Customer||Data Scientist|
|Technology||NoSQL||MapReduce, MPP Database|
Big Data for Operational Intelligence
In addition to user interactions with data, most operational systems need to provide some degree of real-time intelligence about the active data in the system. For example, in a multi-user game or financial application, aggregates for user activities or instrument performance are displayed to users to inform their next actions. Some NoSQL systems can provide insights into patterns and trends based on real-time data with minimal coding and without the need for data scientists and additional infrastructure.
Big Data for Analytics
As applications gain traction and their users generate increasing volumes of data, there are a number of retrospective analytical workloads that provide real value to the business. Where these workloads involve algorithms that are more sophisticated than simple aggregation, MapReduce has emerged as the first choice for Big Data analytics. Some NoSQL systems provide native MapReduce functionality that allows for analytics to be performed on operational data in place. Alternately, data can be copied from NoSQL systems into analytical systems such as Hadoop for MapReduce.
The challenges of Big Data for business are both operational and analytical. New technologies like NoSQL, MPP databases, and Hadoop have emerged to address these challenges and to enable new types of products and services to be delivered by the business. NoSQL, MPP databases and Hadoop are complementary: NoSQL systems should be used to capture Big Data and provide operational intelligence to users, and MPP databases and Hadoop should be used to provide analytical insight for analysts and data scientists. Together, NoSQL, MPP databases and Hadoop enable the business to capitalize on Big Data.
MongoDB and Big Data
Big Data for business means new opportunities for organizations to create value — and extract it. The MongoDB NoSQL database can underpin many Big Data systems, not only as a real-time, operational data store but in offline capacities as well. With MongoDB, organizations are serving more data, more users, more insight with greater ease — and creating more value worldwide. Read our MongoDB Big Data overview to learn more.