Welcome!

XML Authors: Liz McMillan, Anne Buff, Carmen Gonzalez, Paige Leidig, Sanjeev Sharma

Related Topics: XML

XML: Article

Open Source Database Special Feature: An Introduction to Berkeley DB XML

Basic concepts, the shell commands, and beyond

In this article I am going to introduce you to the latest version of the Berkeley DB XML, version 2.2.8. Berkeley DB XML (BDB XML) is built on top of the well-known Berkeley Database (BDB). BDB XML is an open source, native XML database. Like its ancestor, BDB, it's an embedded database. It provides APIs for the Java, C++, Perl, Python, PHP, and Tcl languages. It supports the popular XML query languages XQuery and XPath 2.0. I will show you how to use BDB XML in two ways. This month I will introduce the BDB XML shell, and next month we will explore using BDB XML with Java. BDB XML has a lot of features, and I will try to cover the most important ones.

What's an Embedded Database?
Some of you may be familiar with embedded databases. An embedded database runs within another program. It is not a stand-alone server such as Oracle, DB2, or eXist. It is the programmer's responsibility to invoke the proper API for the database. For example, although Berkeley DB XML has transaction support, in order to activate it, API calls have to be made by the programmer. Many popular relational and native XML databases run in client-server mode. Oracle, DB2, and eXist run as client-server applications, while database server runs as a stand-alone application and many clients can connect to it. Clients and server programs run in different address spaces, probably even on different machines. A connection can be established between them using the JDBC, or ODBC protocols. In an embedded database such as BDB XML, this is not the case; clients and server both run in the same address space, and they are actually the same program. The client manages the Berkeley DB XML through API calls. Next month I will give some Java examples, which will clarify what an embedded database is.

Installation
Installing BDB XML on the Windows operating system is very easy. BDB XML comes with an installer for Windows. If you are using a UNIX-like operating system you have to build BDB XML from the source code. See "Building Berkeley DB XML for UNIX/POSIX systems" for detailed build instructions. I installed BDB XML on my laptop, a 1.4GHz Pentium M processor running on Windows XP Professional with 512Mb main memory, without any problems. The installer will automatically set the necessary Path and Classpath environment variables.

Using dbxml Shell
The shell is located under the bin directory of the BDB XML installation directory. It should be in your Path, so you can run it from any location at the Windows command line.

Invoke the shell by typing "dbxml," and type "quit" to terminate the shell at any time. In order to list all available commands, type "help." To obtain detailed information about a command, type help and the command name. For example "help createContainer" will display usage information of the createContainer command.

createContainer
First of all we have to create a container in which to store our data. A container in BDB XML is similar to a folder. Many XML files can reside in a container. In this article I am going to use XBench sample XML files and queries. You can download the XML sample files and the XML Schema from www.cs.umb.edu/~smimarog/xmlsample/.

Let's create a container called xbench.dbxml. You can, of course, name it anything you want.

dbxml> createContainer xbench.dbxml
Creating node storage container with nodes indexed

The user can choose between two storage types: Wholedoc or Node. The default is Node type storage. If you choose Wholedoc storage, the XML files will be stored as they are with all of the white space preserved. Node storage performs better. The BDB XML documentation suggests not using Wholedoc storage for documents bigger than 1MB.

putDocument
Now we are ready to put some XML data into xbench.dbxml container. In BDB XML the opened container is the default container. We have to open xbench.dbxml before working with it.

dbxml> openContainer xbench.dbxml

Actually, dbxml shell commands on Windows are case insensitive, so it's possible to write opencontainer instead of openContainer, but I am going to follow the established naming conventions here.

dbxml> putDocument sample_10 C:\dictionary10.xml f
Document added, name = sample_10

The putDocument command takes three arguments: the first argument is the unique identifier of the document, the second argument is file name, and the third is either f or s. I chose the name sample_10 as the unique identification of this XML document. C:\dictionary10.xml is the file name, including the path. Finally, the last argument f states that it's a file. Instead of providing a filename it's possible to provide XML data itself within quotes. There are several examples in the "Introduction to Berkeley DB XML" document, which uses an XML string instead of a file name.

Query
As mentioned earlier, BDB XML supports XQuery and XPath 2.0 languages. There will be several examples for each language (see Listings 1-4). BDB XML found 28 results for this query. Note that in order to retrieve the results we have to use "print" command.

setVerbose
BDB XML will produce more explanation about what it does when the setVerbose feature is turned on. This command takes two numeric arguments: level and category. Using this command, let's get more information regarding the XQuery Example2 (see Listing 5).

No indices are used in this query. The execution time is around 48.5 seconds. Execution time is very high for this query for two reasons: this is not a trivial query, and there are no indices created yet. I will conceptually explain the possible execution plan for this query:

For each $entry as /dictionary/e
  For each descendant $desc of $entry
   For each value $val of $desc
   Check if 'hockey' is a substring
    of $val
   return $entry/hwg hw

There are three for loops in this algorithm. At the heart of the three loops there is a very costly substring (contains) operation. Considering that no indices have been created, execution time is pretty good. Creating indices improves the query performance dramatically (see Listings 6-7). (You can find more information about indices in the Indexing section of this article.)

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 (5) 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
SYS-CON Belgium News Desk 12/20/05 01:07:02 PM EST

Open Source Database Special Feature: An Introduction to Berkeley DB XML. In this article I am going to introduce you to the latest version of the Berkeley DB XML, version 2.2.8. Berkeley DB XML (BDB XML) is built on top of the well-known Berkeley Database (BDB). BDB XML is an open source, native XML database. Like its ancestor, BDB, it's an embedded database. It provides APIs for the Java, C++, Perl, Python, PHP, and Tcl languages. It supports the popular XML query languages XQuery and XPath 2.0. I will show you how to use BDB XML in two ways. This month I will introduce the BDB XML shell, and next month we will explore using BDB XML with Java. BDB XML has a lot of features, and I will try to cover the most important ones.

SYS-CON Canada News Desk 12/20/05 12:23:13 PM EST

Open Source Database Special Feature: An Introduction to Berkeley DB XML. In this article I am going to introduce you to the latest version of the Berkeley DB XML, version 2.2.8. Berkeley DB XML (BDB XML) is built on top of the well-known Berkeley Database (BDB). BDB XML is an open source, native XML database. Like its ancestor, BDB, it's an embedded database. It provides APIs for the Java, C++, Perl, Python, PHP, and Tcl languages. It supports the popular XML query languages XQuery and XPath 2.0. I will show you how to use BDB XML in two ways. This month I will introduce the BDB XML shell, and next month we will explore using BDB XML with Java. BDB XML has a lot of features, and I will try to cover the most important ones.

SYS-CON Germany News Desk 12/20/05 11:39:03 AM EST

Open Source Database Special Feature: An Introduction to Berkeley DB XML. In this article I am going to introduce you to the latest version of the Berkeley DB XML, version 2.2.8. Berkeley DB XML (BDB XML) is built on top of the well-known Berkeley Database (BDB). BDB XML is an open source, native XML database. Like its ancestor, BDB, it's an embedded database. It provides APIs for the Java, C++, Perl, Python, PHP, and Tcl languages. It supports the popular XML query languages XQuery and XPath 2.0. I will show you how to use BDB XML in two ways. This month I will introduce the BDB XML shell, and next month we will explore using BDB XML with Java. BDB XML has a lot of features, and I will try to cover the most important ones.

SYS-CON UK News Desk 12/20/05 10:48:56 AM EST

Open Source Database Special Feature: An Introduction to Berkeley DB XML. In this article I am going to introduce you to the latest version of the Berkeley DB XML, version 2.2.8. Berkeley DB XML (BDB XML) is built on top of the well-known Berkeley Database (BDB). BDB XML is an open source, native XML database. Like its ancestor, BDB, it's an embedded database. It provides APIs for the Java, C++, Perl, Python, PHP, and Tcl languages. It supports the popular XML query languages XQuery and XPath 2.0. I will show you how to use BDB XML in two ways. This month I will introduce the BDB XML shell, and next month we will explore using BDB XML with Java. BDB XML has a lot of features, and I will try to cover the most important ones.

XML News Desk 12/20/05 10:12:48 AM EST

Open Source Database Special Feature: An Introduction to Berkeley DB XML. In this article I am going to introduce you to the latest version of the Berkeley DB XML, version 2.2.8. Berkeley DB XML (BDB XML) is built on top of the well-known Berkeley Database (BDB). BDB XML is an open source, native XML database. Like its ancestor, BDB, it's an embedded database. It provides APIs for the Java, C++, Perl, Python, PHP, and Tcl languages. It supports the popular XML query languages XQuery and XPath 2.0. I will show you how to use BDB XML in two ways. This month I will introduce the BDB XML shell, and next month we will explore using BDB XML with Java. BDB XML has a lot of features, and I will try to cover the most important ones.

@ThingsExpo Stories
SYS-CON Events announced today that Harbinger Systems will exhibit at SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Harbinger Systems is a global company providing software technology services. Since 1990, Harbinger has developed a strong customer base worldwide. Its customers include software product companies ranging from hi-tech start-ups in Silicon Valley to leading product companies in the US and large in-house IT organizations.
SYS-CON Events announces a new pavilion on the Cloud Expo floor where WebRTC converges with the Internet of Things. Pavilion will showcase WebRTC and the Internet of Things. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices--computers, smartphones, tablets, and sensors – connected to the Internet by 2020. This number will continue to grow at a rapid pace for the next several decades.
The only place to be June 9-11 is Cloud Expo & @ThingsExpo 2015 East at the Javits Center in New York City. Join us there as delegates from all over the world come to listen to and engage with speakers & sponsors from the leading Cloud Computing, IoT & Big Data companies. Cloud Expo & @ThingsExpo are the leading events covering the booming market of Cloud Computing, IoT & Big Data for the enterprise. Speakers from all over the world will be hand-picked for their ability to explore the economic strategies that utility/cloud computing provides. Whether public, private, or in a hybrid form, clo...
SYS-CON Events announced today that Gridstore™, the leader in software-defined storage (SDS) purpose-built for Windows Servers and Hyper-V, will exhibit at SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Gridstore™ is the leader in software-defined storage purpose built for virtualization that is designed to accelerate applications in virtualized environments. Using its patented Server-Side Virtual Controller™ Technology (SVCT) to eliminate the I/O blender effect and accelerate applications Gridsto...
SYS-CON Events announced today that Red Hat, the world's leading provider of open source solutions, will exhibit at Internet of @ThingsExpo, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Red Hat is the world's leading provider of open source software solutions, using a community-powered approach to reliable and high-performing cloud, Linux, middleware, storage and virtualization technologies. Red Hat also offers award-winning support, training, and consulting services. As the connective hub in a global network of enterprises, partners, a...
As the Internet of Things unfolds, mobile and wearable devices are blurring the line between physical and digital, integrating ever more closely with our interests, our routines, our daily lives. Contextual computing and smart, sensor-equipped spaces bring the potential to walk through a world that recognizes us and responds accordingly. We become continuous transmitters and receivers of data. In his session at Internet of @ThingsExpo, Andrew Bolwell, Director of Innovation for HP’s Printing and Personal Systems Group, will discuss how key attributes of mobile technology – touch input, senso...
The Internet of Things (IoT) is making everything it touches smarter – smart devices, smart cars and smart cities. And lucky us, we’re just beginning to reap the benefits as we work toward a networked society. However, this technology-driven innovation is impacting more than just individuals. The IoT has an environmental impact as well, which brings us to the theme of this month’s #IoTuesday Twitter chat. The ability to remove inefficiencies through connected objects is driving change throughout every sector, including waste management. BigBelly Solar, located just outside of Boston, is trans...
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, will examine 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...
Internet of @ThingsExpo Silicon Valley announced on Thursday its first 12 all-star speakers and sessions for its upcoming event, which will take place November 4-6, 2014, at the Santa Clara Convention Center in California. @ThingsExpo, the first and largest IoT event in the world, debuted at the Javits Center in New York City in June 10-12, 2014 with over 6,000 delegates attending the conference. Among the first 12 announced world class speakers, IBM will present two highly popular IoT sessions, which will take place November 4-6, 2014 at the Santa Clara Convention Center in Santa Clara, Calif...
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 Internet of @ThingsExpo, Jesse Shiah, CEO / President / Co-Founder of AgilePoint Inc., will show what is needed to leverage the IoT to transform your business. He will discuss opportunities and challenges ahead for the IoT from a market and tec...
SYS-CON Events announced today that TeleStax, the main sponsor of Mobicents, will exhibit at Internet of @ThingsExpo, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. TeleStax provides Open Source Communications software and services that facilitate the shift from legacy SS7 based IN networks to IP based LTE and IMS networks hosted on private (on-premise), hybrid or public clouds. TeleStax products include Restcomm, JSLEE, SMSC Gateway, USSD Gateway, SS7 Resource Adaptors, SIP Servlets, Rich Multimedia Services, Presence Services/RCS, Diame...
From a software development perspective IoT is about programming "things," about connecting them with each other or integrating them with existing applications. In his session at @ThingsExpo, Yakov Fain, co-founder of Farata Systems and SuranceBay, will show you how small IoT-enabled devices from multiple manufacturers can be integrated into the workflow of an enterprise application. This is a practical demo of building a framework and components in HTML/Java/Mobile technologies to serve as a platform that can integrate new devices as they become available on the market.
SYS-CON Events announced today that O'Reilly Media has been named “Media Sponsor” of SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. O'Reilly Media spreads the knowledge of innovators through its books, online services, magazines, and conferences. Since 1978, O'Reilly Media has been a chronicler and catalyst of cutting-edge development, homing in on the technology trends that really matter and spurring their adoption by amplifying "faint signals" from the alpha geeks who are creating the future. An...
SYS-CON Events announced today that Aria Systems, the recurring revenue expert, has been named "Bronze Sponsor" of SYS-CON's 15th International Cloud Expo®, which will take place on November 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Aria Systems helps leading businesses connect their customers with the products and services they love. Industry leaders like Pitney Bowes, Experian, AAA NCNU, VMware, HootSuite and many others choose Aria to power their recurring revenue business and deliver exceptional experiences to their customers.
The Transparent Cloud-computing Consortium (abbreviation: T-Cloud Consortium) will conduct research activities into changes in the computing model as a result of collaboration between "device" and "cloud" and the creation of new value and markets through organic data processing High speed and high quality networks, and dramatic improvements in computer processing capabilities, have greatly changed the nature of applications and made the storing and processing of data on the network commonplace.
The Internet of Things (IoT) is going to require a new way of thinking and of developing software for speed, security and innovation. This requires IT leaders to balance business as usual while anticipating for the next market and technology trends. Cloud provides the right IT asset portfolio to help today’s IT leaders manage the old and prepare for the new. Today the cloud conversation is evolving from private and public to hybrid. This session will provide use cases and insights to reinforce the value of the network in helping organizations to maximize their company’s cloud experience.
As a disruptive technology, Web Real-Time Communication (WebRTC), which is an emerging standard of web communications, is redefining how brands and consumers communicate in real time. The on-going narrative around WebRTC has largely been around incorporating video, audio and chat functions to apps. In his session at Internet of @ThingsExpo, Alex Gouaillard, Founder and CTO of Temasys Communications, will look at a fourth element – data channels – and talk about its potential to move WebRTC beyond browsers and into the Internet of Things.
SYS-CON Events announced today that Gigaom Research has been named "Media Sponsor" of SYS-CON's 15th International Cloud Expo®, which will take place on November 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Ashar Baig, Research Director, Cloud, at Gigaom Research, will also lead a Power Panel on the topic "Choosing the Right Cloud Option." Gigaom Research provides timely, in-depth analysis of emerging technologies for individual and corporate subscribers. Gigaom Research's network of 200+ independent analysts provides new content daily that bridges the gap between break...
We certainly live in interesting technological times. And no more interesting than the current competing IoT standards for connectivity. Various standards bodies, approaches, and ecosystems are vying for mindshare and positioning for a competitive edge. It is clear that when the dust settles, we will have new protocols, evolved protocols, that will change the way we interact with devices and infrastructure. We will also have evolved web protocols, like HTTP/2, that will be changing the very core of our infrastructures. At the same time, we have old approaches made new again like micro-services...
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.