Introducing MongoDB 4.x

In this book, we cover how to work with a MongoDB 4.x database, starting with the simplest concepts and moving on to more complex ones. The book is divided into parts or sections, each of which looks at a different scenario.

In this chapter, you are given a general introduction to MongoDB 4.x with a focus on new features and a brief high-level overview of the technology. We also discuss security enhancements, along with backward-incompatible changes that might cause an application written for MongoDB 3 to break after an upgrade to MongoDB 4.x.

In the next chapter, a simple scenario is introduced: a fictitious company called Sweets Complete Inc. that sells confections online to a small base of international customers. In the next two parts that follow, you are introduced to BookSomething.com, another fictitious company with a large database of hotel listings worldwide. Finally, in the last part, you are introduced to BigLittle Micro Finance Ltd., a fictitious company that connects lenders with borrowers and deals with a massive volume of geographically dispersed data.

In this chapter, the following topics are covered:

• A high-level technology overview of MongoDB 4.x
• Significant new features introduced in MongoDB 4.x
• Important security enhancements
• Spotting and avoiding potential problems when migrating from MongoDB 3 to 4