The rise of NoSQL databases marks the end of the era of relational database dominance

But NoSQL databases will not become the new dominators. Relational will still be popular, and used in the majority of situations. They, however, will no longer be the automatic choice.

The era of Polyglot Persistence has begun

Big Data is the driver for NoSQL’s rise, but not the only reason to use NoSQL

Many NoSQL databases are designed to run well on large clusters, which makes them more attractive for large data volumes.

But often people select NoSQL due to easier database interaction in their applications.

Pramod Sadalage and I saw there was no good way to start understanding the concepts that underlie the rise of NoSQL. We wrote this book to tell you what you need to know in order to decide if NoSQL is worth serious investigation for your projects.

To take advantage of this change, you need to be familiar with concepts underlying NoSQL

In the future, organizations will use many data technologies. Data professionals will need to be familiar with these different approaches and know how to match them to different problems. This introduces new ways to think about data modeling, data consistency, and evolution.

Learning the concepts is an important first step, but to really understand you’ll need to get the experience of building representative systems using these technologies.

Introductions Online

If you’re looking for an online introduction to what NoSQL is about, we have a couple of resources.

Pramod wrote an introductory article that summarizes the different forms of NoSQL databases, the distribution models involved and their consequences for consistency, how to choose a NoSQL or SQL database, and the ramifications of schemaless designs.

For a different style of explanation, we’ve also written an introductory infodeck. This explains why relational has been so dominant and what forces have led to NoSQL cracking that dominance. We discuss the principal benefits of a NoSQL approach, but stress that relational databases still have a large role to play, thus our emphasis on polyglot persistence.

(An infodeck takes the basic form of a slide deck, but is designed to be read - not as a projected background to a talk. It uses diagrams and layout, stresses quick reading, yet provides more depth than is allowed by omni-present bullet points.)

Key Points from NoSQL Distilled

When we designed NoSQL Distilled we wanted to include an element for rapid review of the material. We decided to do this by adding a key points section to each chapter, summarizing the chapter in a handful of bullets. We gathered together these key points into a summary web page. This page can act as a reminder for those who’ve read the book and an indication of what’s in the book for people thinking of reading it.

Definitions on the Bliki

My bliki has touched on some of the oft-tricky definitional issues around NoSQL. For a start the term “NoSQL” is an accidental term with no precise definition. We’ve also talked a great deal about polyglot persistence. As we delve more deeply into the database models, we came up with the term aggregate-oriented to help better understand the common characteristics of many forms of NoSQL.


If you’re looking to a one-hour video introduction to NoSQL, this would be my suggestion. It’s a talk I gave at goto Aarhus to kick off a NoSQL track by providing an introduction to the key issues in NoSQL thinking. I talk about the origins of NoSQL, forms of NoSQL data models, the way many NoSQL databases consider the problem of consistency, and the importance of Polyglot Persistence.

NoSQL is part of a wider shift in the world of data. In our keynote for QCon London 2012, Rebecca Parsons and I examined this context looking at the changes in the world of data and the industry’s response. Rebecca adds some interesting insights from the developing world and we consider how all this affects our personal responsibilities as software professionals.

In the spring of 2012 Pramod gave the first talk under the title “NoSQL Distilled” for a geek night in Hamburg organized by the excellent goto conference. The talk focuses on NoSQL data models, comparing them to familiar relational structures, how to do database evolution, and the kinds of projects that make a good fit.

Pramod shares his experiences working with MongoDB on a project for the Democratic Party. He looks at how they loaded data, how they kept it up to date, and how they experimented with different configurations before arriving at the optimal MongoDB setup