Thursday, July 2, 2015

MongoDB Vs MySql

Why use MongoDB instead of MySQL?

Organizations of all sizes are adopting MongoDB because it enables them to build applications faster, handle highly diverse data types, and manage applications more efficiently at scale.
Development is simplified as MongoDB documents map naturally to modern, object-oriented programming languages. Using MongoDB removes the complex object-relational mapping (ORM) layer that translates objects in code to relational tables.
MongoDB’s flexible data model also means that your database schema can evolve with business requirements. For example, the ALTER TABLE command required to add a single, new field to Craiglist’s MySQL database would take months to execute. The Craigslist team migrated to MongoDB because it can accommodate changes to the data model without such costly schema migrations.
MongoDB can also be scaled within and across multiple distributed data centers, providing new levels of availability and scalability previously unachievable with relational databases like MySQL. As your deployments grow in terms of data volume and throughput, MongoDB scales easily with no downtime, and without changing your application. In contrast, to achieve scale with MySQL often requires significant, custom engineering work.

What are common use cases for MongoDB?

MongoDB is a general purpose database that is used for a variety of use cases. The most common use cases for MongoDB include Single View, Internet of Things, Mobile, Real-Time Analytics, Personalization, Catalog, and Content Management.

When would MySQL be a better fit?

While most modern applications require a flexible, scalable system like MongoDB, there are use cases for which a relational database like MySQL would be better suited. Applications that remquire complex, multi-row transactions (e.g., a double-entry bookkeeping system) would be good examples. MongoDB is not a drop-in replacement for legacy applications built around the relational data model and SQL.
A concrete example would be the booking engine behind a travel reservation system, which also typically involves complex transactions. While the core booking engine might run on MySQL, those parts of the app that engage with users – serving up content, integrating with social networks, managing sessions – would be better placed in MongoDB

Are MongoDB and MySQL used together?

There are many examples of hybrid deployments of MongoDB and MySQL. In some cases, it’s a matter of using the right tool for the job. For example, many e-commerce applications use a combination of MongoDB and MySQL. The product catalog, which includes multiple products with different attributes, is a good fit for MongoDB’s flexible data model. On the other hand, the checkout system, which requires complex transactions, would likely be built on MySQL or another relational technology.
In other cases, new business requirements push organizations to adopt MongoDB for the next-generation components of their applications. For example, Sage Group, one of the world’s leading suppliers of business management software and services, integrated MongoDB into its popular Enterprise Resource Planning (ERP) solution for midsize companies. Sage customers now enjoy a higher degree of functionality and personalization as a result of the integration. While many Sage products were originally built on and continue to run on MySQL, the latest user experience functionality centers around MongoDB.
These few exceptions aside, we think MongoDB is almost always a better option than MySQL because of its flexible data model and scalable architecture.

Want to Learn More? Get the RDBMS to MongoDB Migration Guide

Relational databases are being pushed beyond their limits because of the way we build and run applications today, coupled with growth in data sources and user loads. To address these challenges, companies like Salesforce.com, MTV and Cisco have migrated successfully from relational databases to MongoDB. In this white paper, you'll learn:
  • Step by step how to migrate from a relational database to MongoDB.
  • The relevant technical considerations, such as differences between the relational and document data models and the implications for schema design.
  • Indexing, queries, application integration and data migration.
Migration rdbms nosql mongodb

Thursday, June 18, 2015

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Wednesday, June 17, 2015

Getting Started with Berkeley DB Java Edition

http://docs.oracle.com/cd/E17277_02/html/GettingStartedGuide/index.html

Pascal Fares
http://www.cofares.net

ACM TechNews Text Edition, Wednesday, June 17, 2015

> HEADLINES
>
> INDUSTRY NEWS
>
> "Using Virtual Reality to Overcome Fear, Reduce Prejudice"
> "Alabama Researcher Devises a Way to Harness Unused IoT Power"
> "NSF Awards $12 Million to Spur an Engineering Education Revolution"
> "Turning Numbers Into Pictures"
> "Can Phone Data Detect Real-Time Unemployment?"
> "Researchers Link Ebola News Coverage to Public Panic on Social Media"
> "Fixating on Exascale Performance Only Is a Bad Idea"
> "Style Software Gives Fashion Tips After Judging What You Wear"
> "NASA's Robot Event Challenges Robots, Engineers"
> "Samsung, LG Smartwatches Give Up Personal Data to Researchers"
> "Traffic Monitoring to Generate Knowledge"
> "NYU Wireless Researchers Press for New mmWave Safety Metric"
> "President Obama: The Fast Company Interview"
>
> _______________________________________________________________________
> NEWSBRIEFS
>
> INDUSTRY NEWS
>
> Using Virtual Reality to Overcome Fear, Reduce Prejudice
> USA Today (06/17/15) Edward C. Baig
>
> Overcoming phobias, confronting prejudices, tolerating pain, and encouraging healthier living are some of the benefits of virtual reality (VR) technology being explored at Stanford University's Virtual Human Interaction Lab.  Experiments involve subjects contained in a 20-foot by 20-foot space equipped with speakers and a vibrating floor, while high-tech cameras track light-emitting diode sensors worn on the participant's body.  Oculus Rift VR headgear completes the illusion with an overlay of images projected in the subject's field of vision.  "We study the transfer effect--how does an intense virtual reality experience change the way you think of yourself and others?" says lab director Jeremy Bailenson.  One demonstration has participants interact with an earthquake simulation, while another involves looking at an avatar of yourself that can change skin color, gender, and age, and that encounters prejudice from other avatars to help cultivate empathy.  Bailenson thinks the lab will be able to run more extensive experiments once tech companies start installing VR hardware in the home.  "VR is very good for rare moments and impossible moments," he says.  "What happens in a world where anything--the most intense thing that anyone has ever done physically--can happen to everyone at the push of a button?"
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf3fx02384&
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> Alabama Researcher Devises a Way to Harness Unused IoT Power
> IDG News Service (06/16/15) Joab Jackson
>
> University of Alabama at Birmingham (UAB) researchers have developed Aura, a computer architecture that would let people harness all of the unused computer cycles generated by their smart home devices.  Aura can connect hundreds of devices to make them work as a single computational resource.  For example, an Aura-based system could provide extra computational power to complete jobs that otherwise might require a desktop computer to complete.  With Aura, "everybody will become a cloud services provider," says UAB professor Ragib Hasan.  He notes that by 2020, the world will have 26 billion Internet of Things (IoT) devices, all of which will have leftover unused computational cycles.  Hasan says the key to realizing the potential of these devices is having them based on just a few operating systems, much like today's desktop computers predominately run Windows, Mac OS, and Linux.  Agreeing on a single or small number of open IoT platforms will enable developers to write software that can be used effectively across many devices.  Hasan's team already has started developing the needed software, building off of Google MapReduce.  The software can run jobs in a similar manner, but uses smaller IoT devices instead of servers.
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf40x02384&
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> NSF Awards $12 Million to Spur an Engineering Education Revolution
> National Science Foundation (06/15/15) Sarah Bates
>
> The U.S. National Science Foundation (NSF) has awarded $12 million to engineering and computer science departments to enact revolutionary, scalable, and sustainable changes in undergraduate education.  "To flourish in the future, engineering and computer science must attract and retain people from all sectors of society," says NSF's Pramod Khargonekar.  The award, which is divided equally among six universities and will be distributed over five years, is part of NSF's multiyear effort to help universities substantially improve the professional formation of engineers and computer scientists.  A key part of the initiative is support for revolutionizing engineering departments (RED).  "RED focuses on transforming department structure and faculty reward systems to stimulate comprehensive change in policies, practices, and curricula," says NSF's Donna Riley.  The RED projects will build upon successful innovations to improve the undergraduate experience.  The RED investment aligns with the NSF-wide Improving Undergraduate STEM Education initiative.  The six RED awards were given to the Purdue University mechanical engineering department, the Colorado State University department of electrical and computer engineering, the University of North Carolina at Charlotte computer science department, the Arizona State University department of engineering and manufacturing engineering, the University of San Diego school of engineering, and the Oregon State University department of chemical, biomedical, and environmental engineering.
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf41x02384&
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> Turning Numbers Into Pictures
> UTS News Room (06/16/15) Saffron Howden
>
> The University of Technology, Sydney's (UTS) Data Arena is a virtual reality theater four meters high and 10 meters across.  The image encircling the user is 10,000 pixels around, 1,200 pixels high, and two pixels deep.  UTS says the Data Arena, which officially opens next month, will be used by researchers, students, teachers, scientists, artists, industry, and the public to share masses of data, observe it, interact with it, change it, refine it, improve it, and learn from it.  Although the use of big data has become more commonplace, the idea of data provenance, which describes the transaction records that show changes to the data, is only just beginning to be appreciated by mainstream researchers.  For example, UTS professor Cynthia Whitchurch has used Houdini software to make a movie plotting the communal and individual movements of bacteria across a surface.  The Data Arena will enable Whitchurch to interact with the results of the research without the need for additional programming.  "As we're getting into bigger and bigger data, it becomes more and more important to figure out what we've got," says Data Arena lead developer Ben Simons.  "The way to make sense of all this big data is to visualize it."
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf42x02384&
>
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> Can Phone Data Detect Real-Time Unemployment?
> MIT News (06/15/15) Peter Dizikes
>
> A multi-university team of researchers demonstrated that mobile phone data can provide rapid insight into employment levels because people's communications patterns change when they are not working.  Using an automotive plant closing in Europe that resulted in about 1,100 workers unemployed in a town of about 15,000 residents as the dataset for the study, the researchers found in the months following the layoffs, the total number of calls made by laid-off individuals dropped by 51 percent compared with working residents, and by 41 percent compared with all phone users.  In addition, the number of calls made by a newly unemployed worker to someone in the town where they had worked fell by 5 percent, and the number of individual cellphone towers needed to transmit the calls of unemployed workers dropped by about 20 percent.  "People's social behavior diminishes, and that might be one of the ways layoffs have these negative consequences," says Massachusetts Institute of Technology Ph.D. candidate Jameson Toole.  The researchers developed a model that correlates cellphone usage patterns with aggregate changes in employment.  "Using mobile phone data to project economic change would allow almost real-time tracking of the economy, and at very fine spatial granularities," says Northwestern University professor David Lazer.
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf43x02384&
>
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> Researchers Link Ebola News Coverage to Public Panic on Social Media
> ASU News (06/15/15)
>
> Researchers from Arizona State University (ASU), Purdue University, and Oregon State University found news media is effective in creating public panic, according to an assessment of Twitter and Google search trend data.  A team led by ASU professor Sherry Towers collected data on millions of U.S. Ebola-related Google searches and tweets in October 2014 by examining certain phrases.  "When we compared the temporal patterns in these data to the patterns in the number of Ebola-related news stories that ran on major news networks, we found that the peaks and valleys in both almost exactly matched," says ASU professor Carlos Castillo-Chavez.  The team aligned a mathematical contagion model for the spread of disease to the data, and showed how trends in news stories explained nearly all of the variation in the social media.  News videos were especially effective at triggering public concern, with each news clip inspiring tens of thousands of Ebola-related tweets and Internet searches.  The analysis also identified a boredom effect, where after a few weeks, Ebola-related news stories became less and less able to inspire people to perform Ebola-related Google searches or tweets.  Towers is excited about the potential use for this study in future outbreak situations as it provides insight into how news media can manipulate public emotions on a topic.
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf44x02384&
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> Fixating on Exascale Performance Only Is a Bad Idea
> HPC Wire (06/15/15) John Russell
>
> A concentration on realizing exascale computing performance to the exclusion of all else will not address the grand societal and scientific challenges, according to Harvard University lecturer Sadasivan Shankar.  He proposes an emerging materials science model called in silico inverse design, which involves distinct computational requirements that are different and challenging in comparison to direct design.  Shankar theorizes scientific and technological advancements have exceeded the capabilities of direct design, while the challenges confronting society and science share common technological disruptors--design, materials and devices, sensing, automation, and more--best resolved via inverse design.  Shankar defines inverse design as "the ability to use predictive capabilities, to design a material, which when synthesized in the manufacturing line will exhibit targeted properties."  He thinks the push to reach the exascale milestone is being played up while giving the practicality of developing real-world exascale applications little consideration.  Shankar says the uses and requirements of inverse design methodology ought to inform such initiatives.  He believes materials science is particularly relevant to this notion, as the field directly impacts economies and progress.  Shankar says semiconductor materials synthesis is one area that could benefit from inverse design.
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf45x02384&
>
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> Style Software Gives Fashion Tips After Judging What You Wear
> New Scientist (06/16/15) Aviva Rutkin
>
> University of Toronto researcher Raquel Urtasun and colleagues in Spain have developed software that can judge outfits from a photograph and offer suggestions to make them look more chic.  The team gave the software a sense for fashion by showing it thousands of pictures from a popular style website and having it analyze the responses left by users.  The software takes into consideration the user's geographic location, the date the photo was posted, the background of the picture, and written descriptions of the clothing.  "Not everybody has access to an expert," Urtasun says.  "You can imagine something like this being used [to style photos for] dating sites and Facebook profiles."  The researchers also are considering improving the software in the hope it can automate the work of a human stylist.  Urtasun presented the work last week at the Computer Vision and Pattern Recognition conference in Boston.
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf46x02384&
>
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> NASA's Robot Event Challenges Robots, Engineers
> Computerworld (06/12/15) Sharon Gaudin
>
> The U.S. National Aeronautics and Space Administration's (NASA) 2015 Sample Return Robot Challenge was designed to encourage researchers to develop robotics and autonomy software that could be used in future space missions.  The challenge involved 16 robotics teams from around the U.S. and required each team to navigate its robot around a large field, find a range of objects, and bring it back to the starting platform.  NASA hopes the challenge will result in better technology so robots can work autonomously on other planets.  On the first day of the competition, nine teams competed in Level 1, which required the robots to autonomously move off a starting platform and find and retrieve a single object.  Only three of the nine teams were able to make it off the platform and none were able to find the first object.  On the second day, two Level 2 teams had slightly more success: one of the robots found its first object, and a second robot was the only system to find the required three objects.  Despite the modest successes, "We saw teams detecting samples, teams attempting to pick them up and, in several cases, actually collecting the sample," says NASA challenge manager Colleen Shaver.
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf47x02384&
>
>
> Samsung, LG Smartwatches Give Up Personal Data to Researchers
> CNet (06/11/15) Stephen Shankland
>
> Researchers at the University of New Haven's Cyber Forensics Research and Education Group (UNHCFREG) have shown they can extract personal information from two smartwatches because none of the data is encrypted.  From one watch, the researchers were able to retrieve email, calendar, contacts, and pedometer data.  From the other watch, the researchers were able to retrieve health, email, messages, and contacts data.  The researchers noted the ease with which the smartwatches were hacked highlights the importance of data encryption.  "It was not very difficult to get the data, but expertise and research was required," says UNHCFREG director Ibrahim Baggili.  The researchers will present a paper on their work at a digital forensics conference in August.  Last year, UNHCFREG researchers found that many smartphone communications apps were sending messages without using encryption.  In addition, earlier this year the group released Datapp, a Windows program that enables people to check for unencrypted message data.
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf48x02384&
>
>
> Traffic Monitoring to Generate Knowledge
> Universidad Politecnica de Madrid (Spain) (06/15/15)
>
> A new application developed by a team from the Polytechnic University of Madrid could help improve traffic congestion.  BlueTT detects Bluetooth devices in vehicles and generates information on road conditions.  The software, which is used in conjunction with a monitoring system, connects thousands of detectors on the same platform.  Researchers in the university's School of Telecommunications Engineering designed BlueTT to process information such as the travel time between two points and the distribution of traffic at intersections.  The technology can assist city officials and highway authorities with their traffic management efforts.  The software can forecast travel times, provide updates every minute, and automatically adapt specific traffic conditions at all times.  The system has been running in real traffic conditions in Madrid and Seville since late 2013.  The university is finalizing agreements with traffic authorities to use BlueTT.
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf49x02384&
>
>
> NYU Wireless Researchers Press for New mmWave Safety Metric
> FierceWirelessTech (06/12/15) Monica Alleven
>
> Growing interest in using millimeter-wave (mmWave) technology for wireless communications prompted researchers at the New York University (NYU) Wireless multi-disciplinary academic research center to support new safety metrics based on body temperature instead of the existing power density-based standard.  The study used four models representing different body parts, both clothed and unclothed, to gauge the thermal effects of mmWave radiation on humans.  The researchers conducted a simulation showing steady state temperature increases are negligible, even of clothed parts with less blood flow, in comparison to environmental temperature variations.  The exposure intensity for the latter is similar to that likely to be used in a next-generation cellphone.  "Because future devices will operate on a spectrum with different properties than today's communications devices, [U.S. Federal Communications Commission (FCC)] rules and regulations on safety must be reviewed and adjusted accordingly," says NYU Wireless director Ted Rappaport.  The researchers also recommend mmWave devices be evaluated to comply with government exposure guidelines before they are introduced to the consumer market.  In the U.S., the FCC uses the specific absorption rate (SAR) as a metric for exposure compliance for frequencies below 6 GHz--but at higher frequencies, energy absorption is increasingly confined to the surface layers of the skin, making it challenging to define a meaningful volume for SAR evaluation.
> http://orange.hosting.lsoft.com/trk/click?ref=znwrbbrs9_5-dcdex1cf4ax02384&
>
>
> President Obama: The Fast Company Interview
> Fast Company (06/15/15) Robert Safian
>
> In an interview, U.S. President Barack Obama discusses the "digital teams" of technologists that he has brought in to help improve technology across the executive branch of government.  The president notes although his experiences using technology in his two presidential election campaigns gave him an appreciation of how modern technology can be used in the government sector, it wasn't until the spectacular failure of Healthcare.gov that he and his team got serious about changing the way the government approaches technology.  He established the digital teams as a way of bringing in outside technologists, often successful members from leading technology companies, on a temporary basis to find ways of improving federal agencies' use of technology.  He hopes the strategy of forming digital teams using tech experts from outside of government will persist as a model even after his time in the White House ends.  The president also discussed technology's ability to change the way citizens interact with the government, noting the potential for technologies such as online voting to help people who currently feel alienated to reengage with the democratic process, especially the younger generation.  "I think the opportunities for us to think about how tech can empower citizens and make them feel ownership for their government is really important," Obama says.
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Sunday, May 17, 2015