NoSQL For Dummies (2015)

Introduction

I love NoSQL both as a movement and as a technology. It’s a fast-paced, constantly changing area. Barely a week goes by without a new NoSQL database being created to handle a specific real-life problem.

As a movement, NoSQL is interesting in that it started wholly independently of any commercial organization. In fact, it was the brainchild of interested individuals who grouped together and shared ideas. Some core ideas certainly came from large commercial organizations, including the Bigtable paper from Google and the key-value store paper from Amazon, but NoSQL was popularized as open source.

The normal process in software development is that several commercial companies form and compete with one another and gradually the field narrows. Then, once the remaining companies prove their worth, they’re gobbled up by big boys like Oracle, IBM, and Microsoft. Open-source alternatives appear only during the later phases of this cycle.

That’s not the case with NoSQL. Sure, there were a few early commercial players (very early in MarkLogic’s case — way back in 2001). However, the majority of publicly available NoSQL products were created in the open before companies incorporated them into their commercial products.

This book encourages a practical approach to evaluating NoSQL as a set of technologies and products. The book tells you how to determine which ones might meet your needs and how select the most appropriate ones. This information enables you to spot business and technical problems that NoSQL databases can solve.

After reading this book, not only will you be able to identify which type of NoSQL database to use, but perhaps more importantly, you’ll know the questions to ask vendors about their software and services prior to purchasing one.

This book discusses NoSQL in terms of real-life, complex mission-critical applications. Understanding complex enterprise applications allows you to see the flaws and benefits of each NoSQL database, and within contexts similar to the ones you see in your workplace.

This book guides you through this exciting area of technology and highlights how you and your organization can achieve similar benefits to those described. I hope you enjoy the journey!

Foolish Assumptions

My main aim for the book is to expose many NoSQL databases and point out their common features and specific use cases.

My other aim is to point out that NoSQL databases are ready for the big time! I have gone to pains to point out where things can be configured to support this, or where gaps still exist in offerings.

I hope that large enterprises that have not yet widely adopted NoSQL will be reassured by this book. I also hope that it will act as a call to action to NoSQL database vendors in hardening their offerings to support the key needs of each business sector and use cases in such systems.

As this book is considering enterprise classes of problems, I have to be aware of things like long-term development plans, resilient systems, support, and availability of services.

I’ve chosen to cover the following NoSQL databases (plus one search engine):

· Riak: A key-value store

· MongoDB: An aggregate (document) database that primarily stores JSON

· Apache Cassandra: A column store (Bigtable clone)

· Neo4j: A triple and graph store

· MarkLogic Server: Primarily stores XML documents, also JSON, binary, text. Also provides in memory column indexes, a triple store and a search engine

· Redis: An in-memory only key-value store

· Elasticsearch: An Open Source search engine used with many NoSQL databases

I was keen to give a background to a breadth of databases in this book. I also needed to make sure I wasn’t covering the same subject multiple times. I decided to cover one database that primarily manages each data type (document, keys/values, column/tables, triple/graph).

I’m keen to ensure that I don’t give you the impression that each database in each data type area is created equal. Although I concentrate on just one database of each type, I also mention areas where other similar databases are stronger or weaker where appropriate.

I threw in a couple of wildcards. I want to cover Redis as an in memory database. Although in-memory databases have been around for years, Redis provides a NoSQL version of this which is applicable to a different set of problems.

I also cover a commercial NoSQL solution: MarkLogic Server. I include this database for two reasons. Firstly, and most importantly, MarkLogic Server can handle multiple data types whereas the others in my list only concentrate on one particular domain.

Secondly, I love MarkLogic Server – so much so, I joined MarkLogic as a Senior Sales Engineer. MarkLogic Server is also the market leader by software sales in NoSQL databases. (Most companies behind Open Source NoSQL databases only sell extensions to open source software and services, so this is perhaps to be expected!)

Although not strictly a database, Elasticsearch does use NoSQL approaches to its search engine design. NoSQL databases are often used to store semi-structured and unstructured data. This means search engines are an appropriate area to cover. Indeed, Elasticsearch (and Solr/Lucene) are commonly integrated with Open Source NoSQL databases to provide more advanced information retrieval and indexing services.

Icons Used in This Book

Throughout the book, you'll see these little graphic icons to identify useful paragraphs.

The Tip icon marks tips and shortcuts that you can take to make a specific task easier.

The Remember icon marks the information that’s especially important to know.

The Technical Stuff icon marks information of a highly technical nature that you can safely skip over with impunity.

The Warning icon tells you to watch out! It marks important information that may save you headaches. Warning: Don't skip over these icons!

Beyond the Book

NoSQL For Dummies includes the following goodies online for easy download:

· Cheat Sheet: You can find the Cheat Sheet for this book here:

www.dummies.com/cheatsheet/nosql

· Extras: I provide a few extra articles here:

www.dummies.com/extras/nosql

Where to Go from Here

With this book, you have all the information you need to get started on your journey. You can start with Chapter 1, or you can take a look at the table of contents and start with a topic that most interests you.