Welcome!

XML Authors: Liz McMillan, Plutora Blog, Carmen Gonzalez, Elizabeth White, Pat Romanski

Related Topics: XML, Open Source

XML: Article

eXist - An Introduction To Open Source Native XML Database

I am going to introduce you to the open source, free (GNU LGPL license), native XML database eXist (www.exist-db-org)

In this article I am going to introduce you to the open source, free (GNU LGPL license), native XML database eXist (www.exist-db-org). Data is important, no question about it. Data that can't be queried is not very useful. Users expect to have good query response time. From my personal experience and testing, I am confident in saying that eXist is a fairly good database. It has very good query response time, it is very user friendly, it's easy to set up and operate, and it's written in Java, therefore it is platform independent.

This article will show you how to use eXist as a stand-alone database server. If you have any problems or questions you can use the mailing list of eXist. The odds are somebody else had the same problem you have and it's already been answered in the mailing list.

Although eXist is written in Java, you don't have to be a Java programmer in order to use eXist. You can use the graphical user interface (GUI) for almost anything you need to accomplish. Anything that can be done through the GUI can also be done by using command line. This should please the programmers among us who are deeply attached to the command-line tools rather than fancy to GUIs. Let's start exploring eXist.

System Requirements
You need a JRE (Java Runtime Environment) 1.4 or later. This is the only requirement. The documentation states that the package is tested on Linux and Windows XP/2000. Keep in mind that it should work on other operating systems with no problem, because it's platform independent. I set it up on Dell PowerEdge 2600 running on Windows 2003 Server.

Features of eXist
eXist is a native XML database because it is designed and built for XML. Other databases, such as relational databases (Oracle, DB2, MS SQL Server 2000), can handle XML data too, but they are not native XML databases, because they aren't built for XML.

I will list only the most important features of eXist, but if you are interested, you can find a complete list of features at www.exist-db.org:

  • eXist supports many popular XML query languages such as XQuery, XPath, and XSLT
  • It has an automatic indexing features that lets it creates indexes while storing data
  • It supports data update
  • It supports SOAP and XML-RPC protocols
  • It doesn't support database transactions at this time, but it supports concurrent access
Step-by-Step Installation
1.  Get JVM (Java Virtual Machine)
If you don't have a JVM on your system already (1.4 or later), you should download one for free from Sun Microsystems (http://java.sun.com/j2se/). Make sure that your version is at least 1.4. As I write, the latest version of Java is 1.5.0_05 (also known as J2SE 5.0), which is I used for this article (see Figure 1).

2.  Set JAVA_HOME variable
The value of this variable is the full path to your Java installation directory. This is how I set up the JAVA_HOME environment variable on my system:

Control Panel->System->Advanced->Environment Variables->System Variables.

Next I created a new environment variable called "JAVA_HOME," with the value "C:\Program Files\Java\jdk1.5.0_05" (it may be different on your system).

To check if you set up the variable correctly, open a new command prompt window. Type "echo %JAVA_HOME%." You should see the Java installation directory printed on the screen (see Figure 2).

3.  Download eXist
You can download it from www.exist-db.org. For this article I used the most recent development snapshot: "eXist-snapshot-20050805.jar." (Note that the stable version eXist-1.0b2-build-1107.jar is referred to as "ancient." Interestingly enough, it still appears at the top of the list. Get the latest development version instead of the stable version.) (see Figure 3)

In order to run the installation program type:

java -jar eXist-snapshot-20050805.jar

That's it, we have installed it. Now you should see "eXist XML Database" entry in the Start->All Programs menu. Now you are ready to run eXist database server as a stand-alone application (see Figure 4).

Start eXist database server by selecting "eXist Database Startup" at the "eXist XML Database" program menu.

Let's start the client, the GUI that allows us to perform useful database operations such as querying the data and adding a file to or deleting a file from the database.

Start the client by selecting "eXist Client Shell" from the "eXist XML Database" program menu. For now the user "admin" who is the administrator doesn't have a password by default (I recommend creating a password for the admin as soon as possible). (see Figure 5)

Storing XML
Let's use the eXist client program to store XML data. Some of the things that the client program allows a user to do are:

  • create collections
  • store data
  • query data
  • create backup
  • restore files from backup
  • manage users
You should put related XML data under a collection. Just as for the file system, collections help organizing your data better. For example, if you have 100 XML orders, you should probably create an "Orders" collection and store all of the orders under this collection.

If you don't have suitable XML data at hand you use XBench, which is an XML benchmark (see the References section for more information). It comes with a random data generator and predefined set of queries. For this article I used a 10MB XML data file generated by XBench. You can download this data at www.cs.umb.edu/~smimarog/eXist/dictionary10.xml.

Follow these steps:

  • Download "dictionary10.xml" to your system.
  • Create a new collection using eXist client "File->Create Collection." Name it as XBench (see Figure 6). Now, you should see two collections: System and XBench (see Figure 7). The System collection is created by eXist at the installation, and it has system information.
  • Select XBench collection.
  • This collection is empty at the moment.
  • Select "File->Store files/directories." Browse and select "dictionary10.xml."
  • This will store the data. On my system it took less than a minute to store the data. This storage time varies, depending on your system.
Now that we have stored the data we are ready to query it. Note that while storing the data, eXist quietly created default indexes. Default indexes are generally enough for most purposes, but if you are willing to use eXist extensions, you can also create indexes manually, which will improve performance. Check the eXist documentation for details on this topic.

More Stories By Selim Mimaroglu

Selim Mimaroglu is a PhD candidate in computer science at the University of Massachusetts in Boston. He holds an MS in computer science from that school and has a BS in electrical engineering.

Comments (1) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
XML News Desk 11/29/05 07:22:28 PM EST

eXist - An Introduction To Open Source Native XML Database. In this article I am going to introduce you to the open source, free (GNU LGPL license), native XML database eXist (www.exist-db-org). Data is important, no question about it. Data that can't be queried is not very useful. Users expect to have good query response time. From my personal experience and testing, I am confident in saying that eXist is a fairly good database. It has very good query response time, it is very user friendly, it's easy to set up and operate, and it's written in Java, therefore it is platform independent.

@ThingsExpo Stories
Things are being built upon cloud foundations to transform organizations. This CEO Power Panel at 15th Cloud Expo, moderated by Roger Strukhoff, Cloud Expo and @ThingsExpo conference chair, addressed the big issues involving these technologies and, more important, the results they will achieve. Rodney Rogers, chairman and CEO of Virtustream; Brendan O'Brien, co-founder of Aria Systems, Bart Copeland, president and CEO of ActiveState Software; Jim Cowie, chief scientist at Dyn; Dave Wagstaff, VP and chief architect at BSQUARE Corporation; Seth Proctor, CTO of NuoDB, Inc.; and Andris Gailitis, C...
SYS-CON Media announced that Splunk, a provider of the leading software platform for real-time Operational Intelligence, has launched an ad campaign on Big Data Journal. Splunk software and cloud services enable organizations to search, monitor, analyze and visualize machine-generated big data coming from websites, applications, servers, networks, sensors and mobile devices. The ads focus on delivering ROI - how improved uptime delivered $6M in annual ROI, improving customer operations by mining large volumes of unstructured data, and how data tracking delivers uptime when it matters most.
Scott Jenson leads a project called The Physical Web within the Chrome team at Google. Project members are working to take the scalability and openness of the web and use it to talk to the exponentially exploding range of smart devices. Nearly every company today working on the IoT comes up with the same basic solution: use my server and you'll be fine. But if we really believe there will be trillions of these devices, that just can't scale. We need a system that is open a scalable and by using the URL as a basic building block, we open this up and get the same resilience that the web enjoys.
Code Halos - aka "digital fingerprints" - are the key organizing principle to understand a) how dumb things become smart and b) how to monetize this dynamic. In his session at @ThingsExpo, Robert Brown, AVP, Center for the Future of Work at Cognizant Technology Solutions, outlined research, analysis and recommendations from his recently published book on this phenomena on the way leading edge organizations like GE and Disney are unlocking the Internet of Things opportunity and what steps your organization should be taking to position itself for the next platform of digital competition.
In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect at GE, and Ibrahim Gokcen, who leads GE's advanced IoT analytics, focused on the Internet of Things / Industrial Internet and how to make it operational for business end-users. Learn about the challenges posed by machine and sensor data and how to marry it with enterprise data. They also discussed the tips and tricks to provide the Industrial Internet as an end-user consumable service using Big Data Analytics and Industrial Cloud.
How do APIs and IoT relate? The answer is not as simple as merely adding an API on top of a dumb device, but rather about understanding the architectural patterns for implementing an IoT fabric. There are typically two or three trends: Exposing the device to a management framework Exposing that management framework to a business centric logic Exposing that business layer and data to end users. This last trend is the IoT stack, which involves a new shift in the separation of what stuff happens, where data lives and where the interface lies. For instance, it's a mix of architectural styles ...
The Internet of Things (IoT) promises to evolve the way the world does business; however, understanding how to apply it to your company can be a mystery. Most people struggle with understanding the potential business uses or tend to get caught up in the technology, resulting in solutions that fail to meet even minimum business goals. In his session at @ThingsExpo, Jesse Shiah, CEO / President / Co-Founder of AgilePoint Inc., showed what is needed to leverage the IoT to transform your business. He discussed opportunities and challenges ahead for the IoT from a market and technical point of vie...
IoT is still a vague buzzword for many people. In his session at @ThingsExpo, Mike Kavis, Vice President & Principal Cloud Architect at Cloud Technology Partners, discussed the business value of IoT that goes far beyond the general public's perception that IoT is all about wearables and home consumer services. He also discussed how IoT is perceived by investors and how venture capitalist access this space. Other topics discussed were barriers to success, what is new, what is old, and what the future may hold. Mike Kavis is Vice President & Principal Cloud Architect at Cloud Technology Pa...
The Internet of Things (IoT) is rapidly in the process of breaking from its heretofore relatively obscure enterprise applications (such as plant floor control and supply chain management) and going mainstream into the consumer space. More and more creative folks are interconnecting everyday products such as household items, mobile devices, appliances and cars, and unleashing new and imaginative scenarios. We are seeing a lot of excitement around applications in home automation, personal fitness, and in-car entertainment and this excitement will bleed into other areas. On the commercial side, m...
Dale Kim is the Director of Industry Solutions at MapR. His background includes a variety of technical and management roles at information technology companies. While his experience includes work with relational databases, much of his career pertains to non-relational data in the areas of search, content management, and NoSQL, and includes senior roles in technical marketing, sales engineering, and support engineering. Dale holds an MBA from Santa Clara University, and a BA in Computer Science from the University of California, Berkeley.
The Industrial Internet revolution is now underway, enabled by connected machines and billions of devices that communicate and collaborate. The massive amounts of Big Data requiring real-time analysis is flooding legacy IT systems and giving way to cloud environments that can handle the unpredictable workloads. Yet many barriers remain until we can fully realize the opportunities and benefits from the convergence of machines and devices with Big Data and the cloud, including interoperability, data security and privacy.
The 3rd International Internet of @ThingsExpo, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that its Call for Papers is now open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
"People are a lot more knowledgeable about APIs now. There are two types of people who work with APIs - IT people who want to use APIs for something internal and the product managers who want to do something outside APIs for people to connect to them," explained Roberto Medrano, Executive Vice President at SOA Software, in this SYS-CON.tv interview at Cloud Expo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
Performance is the intersection of power, agility, control, and choice. If you value performance, and more specifically consistent performance, you need to look beyond simple virtualized compute. Many factors need to be considered to create a truly performant environment. In his General Session at 15th Cloud Expo, Harold Hannon, Sr. Software Architect at SoftLayer, discussed how to take advantage of a multitude of compute options and platform features to make cloud the cornerstone of your online presence.
In this Women in Technology Power Panel at 15th Cloud Expo, moderated by Anne Plese, Senior Consultant, Cloud Product Marketing at Verizon Enterprise, Esmeralda Swartz, CMO at MetraTech; Evelyn de Souza, Data Privacy and Compliance Strategy Leader at Cisco Systems; Seema Jethani, Director of Product Management at Basho Technologies; Victoria Livschitz, CEO of Qubell Inc.; Anne Hungate, Senior Director of Software Quality at DIRECTV, discussed what path they took to find their spot within the technology industry and how do they see opportunities for other women in their area of expertise.
DevOps Summit 2015 New York, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that it is now accepting Keynote Proposals. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long development cycles that produce software that is obsolete at launch. DevOps may be disruptive, but it is essential.
Almost everyone sees the potential of Internet of Things but how can businesses truly unlock that potential. The key will be in the ability to discover business insight in the midst of an ocean of Big Data generated from billions of embedded devices via Systems of Discover. Businesses will also need to ensure that they can sustain that insight by leveraging the cloud for global reach, scale and elasticity.
The Internet of Things will greatly expand the opportunities for data collection and new business models driven off of that data. In her session at @ThingsExpo, Esmeralda Swartz, CMO of MetraTech, discussed how for this to be effective you not only need to have infrastructure and operational models capable of utilizing this new phenomenon, but increasingly service providers will need to convince a skeptical public to participate. Get ready to show them the money!
The 3rd International Internet of @ThingsExpo, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that its Call for Papers is now open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
Connected devices and the Internet of Things are getting significant momentum in 2014. In his session at Internet of @ThingsExpo, Jim Hunter, Chief Scientist & Technology Evangelist at Greenwave Systems, examined three key elements that together will drive mass adoption of the IoT before the end of 2015. The first element is the recent advent of robust open source protocols (like AllJoyn and WebRTC) that facilitate M2M communication. The second is broad availability of flexible, cost-effective storage designed to handle the massive surge in back-end data in a world where timely analytics is e...