In modern software applications, often there is the necessity to manage very large amounts of data. These are often unstructured and their schema may vary according to marketing rules or other external factors which you can't control. In this scenario, relational databases would not be the right choice.
This is where NoSQL databases come in, in particular the graph-based ones.
In graph databases, data is modeled like in a graph. Each piece of information is a node and links between them are edges.
They are a very young product and they were designed to satisfy modern necessities regarding the management of large amounts of data, often without a fixed schema or with a fluid schema that may vary very often even when the software is in production. Furthermore, this data could be related to each other in multiple ways. A great example of this is social networks.
They must manage billions of records and connect, traverse, and perform queries in a snap.
OrientDB is an open source document-graph NoSQL database born at the end of the last decade, but its algorithms and concepts have a long story that began in the late 90s when its authors wrote an object database.
Now, OrientDB is a very strong, mature, and robust platform. It has reached Version 1.5.0 and its community and committers are very active, and they are already working on a new version. OrientDB is used in production by many companies.
Some of these companies are listed at https://github.com/nuvolabase/orientdb/wiki/Production-Deployments.
This book is intended to be a beginner's guide to help you get started with OrientDB. It is a quick reference to the most common OrientDB tasks, from administrative ones to deployment, from designing a graph database to the different ways to perform queries and consume data.
Chapter 1, Installing OrientDB, provides an introduction to the OrientDB world as well as a quick guide to help you set up and run OrientDB.
Chapter 2, Administering OrientDB, explains the database architecture, data files structure, user management and security, and administration tools.
Chapter 3, Programming OrientDB, shows you how to perform operations against the database, covering the multiple modes supported by OrientDB to interact with it.
Chapter 4, Performance Tuning, gives some advice and tips for every possible use, since OrientDB can be used in several different scenarios.
Chapter 5, Advanced Features, covers several advanced features provided by OrientDB. And since it is a very active project, many of them are released and updated continuously. In this chapter, some of the features are discussed.
Appendix, contains quick references to the OrientDB embedded SQL-like parser and the native Java API interface as well as a list of the many configuration parameters available to control the server behavior. This appendix is available at http://www.packtpub.com/sites/default/files/downloads/9956OS_Appendix.pdf.
To complete the book, a convenient list of links and references to useful online sources about OrientDB is provided as well. This list is available at http://www.packtpub.com/sites/default/files/downloads/9956OS_OrientDB_1.5.0.pdf.
To run OrientDB, it is necessary that you have a system capable to run at least Java SE 6.
To build from source code, it is necessary to have at least JDK 6, the Ant tool Version 1.6.5 or above, and Maven.
To get the source code, you can use Git, but this is not mandatory since the entire repository hosted by GitHub may be downloaded as a ZIP file.
This book is great for database designers, developers, and systems engineers.
It is assumed that you are familiar with NoSQL concepts and have some experience with Java already.
For some topics like clustering, it's assumed that you have a basic knowledge of networking principles.
In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.
Code words in text are shown as follows: "Download the orientdb-1.3.0.tar.gz file from the OrientDB site and extract its content in a directory on your system."
A block of code is set as follows:
mail.send({
profile: "default",
to: "[email protected],[email protected]",
cc: "[email protected]",
subject: "Something happend!",
message : "Alert! Something happend on OrientDB server!"
});When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
ODocument doc = new ODocument();
for(int i=0; i< 9999999; i++){
doc.reset(); //here you will reset the ODocument instance
doc.setClassname("Author");
doc.field("id", i);
doc.field("name", "John");
doc.save();
}Any command-line input or output is written as follows:
ORIENTDB_DIR="YOUR_ORIENTDB_INSTALLATION_PATH" ORIENTDB_USER="USER_YOU_WANT_ORIENTDB_RUN_WITH"
New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "Clicking on the Next button moves you to the next screen."
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