Showing posts with label Web Mining. Show all posts
Showing posts with label Web Mining. Show all posts

Tuesday, December 9, 2014

Distributed database vs Distributed DBMS

Distributed database: a collection of multiple, logically interrelated databases distributed over a computer network.
However,
Distributed DBMS: the software system that permits the management of the distributed database and makes the distribution transparent to the users.

Saturday, March 15, 2014

What is NoSql ?

No matter who you are I am sure that is has already happened one day you ask yourself this question: What is nosql ?  Asking many people out there  what they know about nosql, many of them will mention mostly one of the following terms: cassandra, mongoDb, couchDb, Hbase , something related to big data , to name only these few.
   In fact nosql does not mean that SQL is forbidden or that we should never use it rather nosql raises our attention to the fact that for certain problems other storage solutions are well suited. Therefore finish the era of one fit all, where for any problem at hand we had to automatically use a given version of sql database (mysql, oracle, sql server, etc...). In order to simplify our understanding some key points are going to  guide us and they are:

--Basic definitions:
 NOSQL is NOT ONLY SQL 
 NOSQL is not NO SQL
 NOSQL = next generation of databases
 NOSQL = modern web-scales databases
A NoSQL database provides a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases

-- Why NOSQL is used today ?
 -Size: unprecedented data growth
-Connectedness
-Semi-structure
-Architecture

-- Four (04) emerging NOSQL categories:
-Key-value
-Graph DB
-BigTable
-Document

a) Key-value:
   e.g: -Dynamo
          -Voldemort
          -Riak
         
b) Big Table:
  e.g: -HBase
         -Hyper Table
         -Cassandra
c) Document database:
   e.g: -CouchDB
          -MongoDB
          -IBM lotus

d) Graph database:
   e.g: -Neo4j
          -AllegroGraph
          -Sones graphDB
          -InfoGrid

--NoSQL is not  traditional database, how do I query it ?
  
1. RESTful interfaces using HTTP as an access API
2. Query languages other than SQL:
   - GQL: Google table
   -SPARQL: Semantic web
   -Gremlin: graph traversal language
3.Query APIs
  -Google BigTable datastore API
  -The Noo4j traversal API

--Who is successfully using NoSql ?
  -Facebook
  -Google
  -Yahoo
  -Twitter
  -GitHub
  -Linkedin
  - Maybe you who is reading this post right now (LOL !)

Coming to the end of this post, let me reaffirm again that I am not an expert on nosql but throughout this post I personally wanted to share with you my humble understanding of this promising technology that within a very short period has shown us what it is up to. In a case you have something too to share with us, please don't hesitate to drop a comment. If you are planning to get started with using Nosql I am sure that after reading this post nothing will be like before anymore and that you will confidently move on with your investigations on NoSql.

references:
1. http://www.slideshare.net/thobe/nosql-for-dummies
2. http://en.wikipedia.org/wiki/NoSQL


Saturday, September 7, 2013

Big Data, what is it ?

Few years ago a company needed only a traditional database system such as Oracle, mysql , MS Server , Sybase etc to smoothly run its business. Nowadays for the same company to remain competitive, there is a need to take into account not only employees , transactional records and others but online data, and more. All possible sources of information related to that particular company need to be analyzed properly. However our traditional data cannot easily store or manage these highly unstructured data. NoSql related databases enter into the play...
In short the following figure shows a view of Big Data within an organisation:

  
With the current trends, willing or not any company today aspiring to survive must join the dance. In general Big Data is a term used to describe the exponential growth and availability of both structured and unstructured data. While a properly analysis of these massive data may offer enterprises tremendous benefits, there are also risks of being overwhelmed. 
  • How can you use it to suit your need ?
  • How can you analyze it all ?
  • How do you store all these data ?
  • How do you extract intelligence from it ?
  • Do you have enough to professionals to handle and analyze it ?
 As stated by Scott Zucker : Small data is gone. Data is just going to get bigger and bigger and bigger, and people just have to think differently about how they manage it.

Thursday, August 22, 2013

It is all about Big Data


1.   Introduction
Tim O’Reilly, by declaring in his famous article “What is Web 2.0” that “data is the next Intel Inside” made indeed a visionary declaration for data revolution. However creating intelligent values from Big Data cannot be accomplished by just aggregating large amounts of data or performing analysis. The necessity to make sense and maximize utilization of such vast amounts of data for knowledge discovery and decision-making is crucial to scientific advancement. This has led to some recent initiatives in both theory and practice in order to find some techniques to handle Big Data challenges.

2.   Research direction
Some of the active areas of research under Big Data are:
§      Text- and data-mining of historical and archival material.
§      Social media analysis, including sentiment analysis
§       Knowledge Mapping from Big Data Sources
§      Crowd-sourcing and big data
§      Privacy Preserving Big Data Collection / Analytics
§      Relationship between ‘small data’ and big data
§      NoSQL databases and their application
§      Big data and the construction of memory and identity
§      Big data and archival practice
§      Construction of big data
§      Big data in Heritage
§      Etc…

3.   Challenges
As pointed out in [1, 2, 3], applying Big Data analytics to the field of development faces several challenges. Some challenges relate to the data including its acquisition and sharing and overarching concern over privacy, and others pertain to its analysis. Privacy is the most sensitive issue, with conceptual, legal, and technological implications. Access and sharing are not the least given the reluctance of private companies and other institutions to share data about their clients and users, as well as about their own operations. Obstacles may include legal or reputational considerations, a need to protect their competitiveness, a culture of secrecy, and, more broadly, the absence of the right incentive and information structures. There are also institutional and technical challenges—when data is stored in places and ways that make it difficult to be accessed, transferred, etc.  Another key challenge is the analysis itself.  Working with new data sources brings about a number of analytical challenges. The relevance and severity of those challenges will vary depending on the type of analysis being conducted, and on the type of decisions that the data might eventually inform. The analysis challenge can be splitted into three distinct categories: (1) getting the picture right, i.e. summarizing the data (2) interpreting, or making sense of the data through inferences, and (3) defining and detecting anomalies.

4.   Applications
Big Data holds a tremendous wealth of information and, like nanotechnology and quantum computing, it will shape the twenty-first century with highly promising applications. As presented in [1, 3], Big Data if properly analyzed can offer the opportunity for an improved understanding of human behavior that can support the field of global development in three main ways:
  a) Early warning: early detection of anomalies in how populations use digital devices and services can enable faster response in times of crisis;
  b) Real-time awareness: Big Data can paint a fine-grained and current representation of reality which can inform the design and targeting of programs and policies;
  c) Real-time feedback: the ability to monitor a population in real time makes it possible to understand where policies and programs are failing and make the necessary adjustments.

5.   Conclusion
Despite the overwhelming challenges Big Data present potential growing applications and concerns ranging from government, industries to academia as illustrated in [2, 3].  Therefore the aim of this article has been to present some potential research directives on Big Data as well as its challenges and potential applications.

References:

[1] “Big Data for Development: Challenges and Opportunities”, Global Pulse, May 2012

[2] “Big data in canada: challenging complacency for competitive advantage”. Nigel Wallis, December 2012.

[3]  "Algorithm and approaches to handle large Data- A Survey", Chanchal Yadav, Shuliang Wang ,Manoj Kumar, IJCSN, Vol 2, Issue 3, 2013.