CAP Theroem

                       CAP THEOREM

what is CAP?

CAP means Consistency Availability and Partition tolerance

CAP theorem, also known as Brewer's theorem

This theorem is about database

This Theorem states that it is impossible for a distributed computer system to simultaneously provide all three i.e, the database cannot have consistency availability and partition tolerance at one

• Consistency : all nodes see the same data at the same time
• Availability :a guarantee that every request receives a response about whether it was successful or failed
• Partition tolerance :the system continues to operate despite arbitrary message loss or failure of part of the system

At present world we see relational database i.e oracleDB,SQL SERVER,mySQL,DB2 etc,these database support only relation data in the form of tables but what about non-relational data i.e behavioral data 

what is behavioral data?

Data about an entity example consider that your searching in Google when you are logged in with Google account rater than keeping your account in data based(i.e relational one) they collect the data about what your are searching? so that when you are searching and when you are logged in,if you search the first preference will be given to the behavioral data of yours and so that no need to type the whole sentence again.

This type of data is useful for analysis business and people.

In NoSQL we can use 4 type of data:

Document store

The central concept of a document store is the notion of a "document". While each document-oriented database implementation differs on the details of this definition, in general, they all assume that documents encapsulate and encode data (or information) in some standard formats or encodings. Encodings in use include XML, YAML, and JSON as well as binary forms like BSON, PDF and Microsoft Office documents (MS Word, Excel, and so on). 

Different implementations offer different ways of organizing and/or grouping documents:

• Collections
• Tags
• Non-visible Metadata
• Directory hierarchies

Graph

This kind of database is designed for data whose relations are well represented as a graph (elements interconnected with an undetermined number of relations between them). The kind of data could be social relations, public transport links, road maps or network typologies, 

Key–value store

Key–value stores allow the application to store its data in a schema-less way. The data could be stored in a datatype of a programming language or an object. Because of this, there is no need for a fixed data model.

Column Family Stores

These were created to store and process very large amounts of data distributed over many machines. There are still keys but they point to multiple columns. The columns are arranged by column family.

For maintaining these database different vendors have different softwares

This NoSql is famous by this name BigData. 

After few days if you don't know about it,you may not be eligible for employment in database field.

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Difference between the XML and Database ?

Is XML and DATABASE are same ?

Can I use XML instead of DATABASE ?

Extensible Markup Language (XML) and databases are two different methods for storing large amounts of data in an organized fashion. There are both similarities and differences between them. Determining which to use depends on your needs and may actually be a combination of both

Difference between the XML and HTML

XML was designed to transport and store data.

HTML was designed to display data.

Understanding XML

• XML is a standardized method of describing information, or data, established by the W3C. It is a tag based language, similar to HTML, but using stricter standards. Unlike HTML, tags are not predefined - they can be established based on the users needs at design time.

Understanding Databases

• Databases are composed of collections of data organized into tables, with data stored in rows and columns. The columns define the type of data to be stored, such as a purchase date and customer IDs, and each row contains an instance of that data. Databases are often relational, which means that different data in multiple tables may be related by a key value. For example, a customer ID may be in the purchase table and a customer table, holding the customer information in the latter, and the specific information on the purchase in the former.

Similarities

• XML and databases are similar in that they are both structured methods of organizing data. Each can contain a key value associated with one or more instances of data items. In XML, this would be multiple tags with the same name, such as <product>item1</product><product>item 2</product>. In a database, this is represented by a unique value of some type, for instance the customer order number, and one row of data for each product.

Differences

• XML stores all of it's data in an XML file, which can be created and designed in a simple text editor. No special tools are required. A database application generally stores data in a specific data file, possibly reducing portability. In addition, databases are a specific application which requires some type of installation and a knowledge of structured query language (SQL) to access.

  Overall, while both are good storage solutions, the determination of which is best depends on the type of data to be stored. According to IBM's analysis of XML and databases, XML is most suited for "document-like storage" of data with a "semi-structured" format. Data which is heavily based on standard database design techniques, such as entity-relationship diagrams, is better suited for databases.

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Difference between the C++ and JAVA ?

Difference between the C++ and JAVA ?

Difference between C++ and JAVA

This article mainly concentrate on the exploration of the power of the JAVA.

We can implement all the features which are present in the JAVA, in C++ also except the two features.

1. Security 
2. Platform Independence.

The main difference between the C++ and JAVA is SECURITY and PLATFORM INDEPENDENCE.

1. SECURITY :
                            SECURITY for any language means accessing its data, but which kind of data ?
 here the language security is accessing its PRIVATE data i.e., which is declared as PRIVATE.

In C++:
         Both C++ and JAVA are Object Oriented Programming languages, and both of them supports the feature i.e, Data hiding ( data is hided behind the object if you want to access those data you have to its object). This feature of the OOP is also called as security. 
But is C++ we can break this feature that means we can access those data without its object.

How ?

example:
class data
{
   private:
   int a;

   public:
   void showA()
   {
          cout<<"a value is:"<<a;
    }
};

void main()
{
     data d;
     int *ptr;
     //accessing address of the d
    ptr(int)=(int)&d;
     //print the value of before the assignment through the pointer.
     d.showA();  //probably you may get garbage value
    //assign value to 'a' through the pointer  
     *ptr=2;
     //now print the value
     d.showA(); //you will get output a value is :2
     
getch();
}

In JAVA:

Here actually there is no concept of 'pointers' so that you can't make access of the another variable illegally. So that JAVA is more secure.


2. PLATFORM INDEPENDENCE:
        PLATFORM independence means the program you have written should be run on all machines.

IN C++:
                What a compile does is it will convert the source language into the assembly level language. In the process of the conversion of these high level instructions into assembly level language it will convert according to the configuration of the machine (CPU registers and other other elements) So that if you run your final output in another system with different configuration means other CPU then it won't work because the CPU is different. So Platform dependent.

IN JAVA:

            The main Problem with C++ is if the processor is not the same as you developed in then it will not work. So we should have to develop code for common MACHINE (CPU). So in JAVA there is a machine which is software machine which is common wherever you get installed. I mean here we are providing a Virtual Machine to replace the problem of requirement of same MACHINE. This software Machine is called JAVA VIRTUAL MACHINE.

Only by these 2 reasons JAVA is powerful.
                       
This article is to the differentiate C++ and JAVA.
                                                                  

    

                                                                                                                  by
                                                                                                                  K.Partha Saradhi Reddy.
                                                                                                                  G.V.N.Yaswanth.
                                                                                                                  R.S.M.S. Vamsi Krishna.

For any queries mail us:  programmersband@gmail.com




            




             

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which language is suitable for web development JSP or PHP or ASP or RIALS ON RUBY ?

Which language is best suited  for web development ?

Got confused with the programming language selection for the web development ?

         Among all of those the selection of programming language is difficult. Because you're familiar with all of those. The selection of the language for the web development is based on your requirement.

•  If your requirement is to complete the project very fast then you have to choose ASP.NET.

                       That means if you want to complete your project within a small amount of time then you have to choose the ASP.net. But the hosting for ASP is very cost than the PHP. If you can pay, then you must choose the ASP.NET. At this time you don't have to bother about the money. Because, if you choose this you can get the ready-made script for everything. And another important factor is that very good developer flexibility. 

Benefits:

1. Programmer Flexibility.

2. Fast completion of Project.

3. Very good Script support.

but 

hosting cost is little high.

• If your requirement is to complete the project at cheap and secure 

                                  That means if you want to complete your project at cheap and that too with high security then you should choose PHP. Because PHP offers high security and very cheap than other languages. And the database server MYSQL is also free. So you can choose it blindly to develop your project.

Benefits:

1. Fast development.

2. Easy to learn.

3. Platform independent.

4.Developer flexibility is high.

5. Finally it is free.

• if your requirement is to build a more secure product then you have to choose the JSP.

                That means if you want to do a project using JSP means you're looking for a product that should be more secure. And another important thing is JSP hosting also little costly like ASP. You might think that it is open source so that it may be cheap. But the thing is, it is little costly for hosting.

Benifits:

1. Offers high security.

bBut

1. Complex to develop huge projects.

2. Hosting cost is high.

3. Handling is difficult.

               All these information is from analyzing the practical things that we have faced in the real time. So make your choice.

                                                           by

                                                           K.Partha Saradhi Reddy.

                                                           G.V.N.Yaswanth.

                                                           R.S.M.S. Vamsi Krishna.

     If you have any good experience then mail us.

                                     email_id: programmersband@gmail.com

  

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Windows NT Kernel

                                                   Windows NT Kernel
  
Everyone in Know the Linux kernel but don't maximum student don't use it but everyone use windows XP or Windows 7 Now-a-days 8 but don't know the kernel inside it,which is like heart of windows OS.

The architecture of Windows NT, a line of operating systems produced and sold by Microsoft, is a layered design that consists of two main components, user mode and kernel mode. It is a preemptive, re-entrant operating system, which has been designed to work with uniprocessor and symmetrical multi processor (SMP)-based computers. To process input/output (I/O) requests, they use packet-driven I/O, which utilizes I/O request packets (IRPs) and asynchronous I/O. Starting with Windows 2000, Microsoft began making 64-bitversions of Windows available—before this, these operating systems only existed in 32-bit versions.

Programs and subsystems in user mode are limited in terms of what system resources they have access to, while the kernel mode has unrestricted access to the system memory and external devices. The Windows NT kernel is known as a hybrid kernel. The architecture comprises a simple kernel, hardware abstraction layer (HAL), drivers, and a range of services (collectively named Executive), which all exist in kernel mode.

User mode in Windows NT is made of subsystems capable of passing I/O requests to the appropriate kernel mode software drivers by using the I/O manager. Two subsystems make up the user mode layer of Windows NT: the Environment subsystem (which runs applications written for many different types of operating systems), and the Integral subsystem operates system specific functions on behalf of the environment subsystem. Kernel mode in Windows NT has full access to the hardware and system resources of the computer. The kernel mode stops user mode services and applications from accessing critical areas of the operating system that they should not have access to.

Architecture of Windows NT:

For more :http://en.wikipedia.org/wiki/Architecture_of_Windows_NT

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Mono Software

                                                             Mono Software

Mono is a free and open source project led by Xamarin (formerly by Novell and originally by Ximian) to create an Ecma standard compliant .NET Framework-compatible set of tools including, among others, a C# compiler and a Common Language Runtime.

The stated purpose of Mono is not only to be able to run Microsoft .NET applications cross-platform, but also to bring better development tools to Linux developers. Mono can be run on many software systems including Android (and most other Linux distributions), BSD, iOS, OS X, Windows, Solaris, and some for game consoles such as PlayStation 3, Wii, and Xbox 360.

Its mean by using this application we can develop DotNet applications in Linux environment by using C# language.


The File architecture of Mono is:                                                                                                                                     

For More view this:http://en.wikipedia.org/wiki/Mono_(software)

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Amazing postbox by facebook

Amazing technology by Facebook:

When you observe that Facebook post box will accepts all kind of data. But even though if you enter the tags it will not create any error. This is the real power of Facebook. Even though this is a small thing to the normal users but once as a programmer if you think about it then we will definitely shocked and amazed by the Facebook technology. It gives us a lot of complex programs output. 

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Malware attack

Android Malware Infections Increase By 700%

Approximately 85% of all mobile malware attacks since 2011 occured on Android smartphones.

When it comes to the world of internet security and malware, being the biggest fish in the sea also makes you the biggest target. Such was the case when Windows operating systems dominated the PC landscape in the 90s, and such is the case today in the mobile sphere with Android phones. The platform is fast becoming the mobile operating system of choice, but its rampant growth combined with its open source nature is an ideal breeding ground for virus and malware distribution. Tracking reports by security firm McAfee have revealed that in the last year, malware breaches have grown by an astronomical 700%, putting the Android at approximately 85% of reported malware instances.

The attacks themselves range from standard email and SMS sending malware, to mobile botnets and trojans. Thumb drive, password-stealing, and URL-based malware have sample increases in the millions. Mobile ransomware in particular has become an especially prominent tool for cybercriminals in recent months. Ransomware infects a mobile system to delete photos and personal files, with the demand that users pay an amount of money to restore their phone back to its original state.

So why is Android seeing such high malware figures compared to Apple's iOS? Part of the reason, just as for Android's piracy figures, is the open-source nature of Android but there are other problems. Google's official malware scanner Bouncer, which scans apps to ensure they are not malware, only scans programs that come through the Google Play Store. Any malware coming from third-party sources, which is very common on an open-source platform, won't be inspected by Bouncer.

My instinctive reaction to this is that users should be better educated on how to make their devices more secure, but frankly, a 700% increase implies that steps should be taken to make the platform itself more secure. Google may already have some solutions in the works, including the recent updates to the Android Billing System, which should make purchase-related security upgrades much easier to implement.

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Efficient programming..

YOU CAN BECAME AS AN EFFICIENT PROGRAMMER....

Even though you programmed very well that will not be concerned for your performance. If you coded in a standard way then it will gives a fast understanding for you and others. If you code in a standard way, if there may any bugs in your code then those will be easily recognizable.

Check out the Coding standards in JAVA.

JAVA coding standards

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DART PROGRAMMING LANGUAGE.

A NEW APPROACH FOR WEB DESIGNING.

Dart is a class-based, object-oriented language with lexical scoping, closures, and optional static typing. Dart helps you build structured modern web apps and is easy to learn for a wide range of developers.

Dart can be compiled to JavaScript, so you can use it for web apps in all modern desktop and mobile browsers. Our JavaScript compiler generates minimal code thanks to tree-shaking. Dart apps can also run on the server, in a stand-alone Dart VM.

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Programming languages ranking

Again JAVA is NO 1:

Java is number one again after it lost the top position to C 10 months ago. Boosted by the success of Android phones, Java has gained most market share of all languages last half a year (+2.03%). Python is also rising again (+1.07% last half a year). It is rivaling PHP to become the most popular interpreted language.

 The index is updated once a month. The ratings are based on the number of skilled engineers world-wide, courses and third party vendors. The popular search engines Google, Bing, Yahoo!, Wikipedia, Amazon, YouTube and Baidu are used to calculate the ratings. Observe that the index is not about the best programming language or the language in which most lines of code have been written.

The index can be used to check whether your programming skills are still up to date or to make a strategic decision about what programming language should be adopted when starting to build a new software system.

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Android next version name ?

                              ANDROID VERSIONS...

Fancy a slice of Key Lime Pie? A Google employee has served up a tasty treat of a cartoon giving us the strongest hint yet for the name of the hotly anticipated next Android update.

Google software engineer Manu Cornet, who also produces the tech-themed webcomicBonkers World, doodled the evolution of Android pictured above. The image is "just for fun" and we shouldn't read much into it, but with rumours of the Key Lime Pie name swirling since the start of this year, this is a pretty strong indication from inside Google that the next version will indeed be lime-flavoured. 

Google names each new version of the Android software for phones and tablets after a veritable sweet trolley of tasty treats, arrayed in alphabetical order. We've so far feasted on Cupcake, Donut, Eclair, Froyo, Gingerbread, Honeycomb, Ice Cream Sandwich and Jelly Bean, with Key Lime Pie set to be the next sweet treat to get the Android treatment.

The latest version of Android is Jelly Bean 4.2, which adds the clever Photo Sphere camera feature and debuts on the Google Nexus 4.

Android updates aren't without controversy, however. Jelly Bean 4.2 broke Bluetooth on many phones and managed to miss out December from some apps, forcing Google to rush out ahasty 4.2.1 update. And phone manufacturers struggle to get new software onto your blowers -- even claiming that updates can damage your phone.

As a result, most phone fans are stuck with what they feel is out-of-date software even on brand new phones. As of November, Ice Cream Sandwich is on a quarter of Android phones but more than half still run Gingerbread -- three generations old, not including the tablet-focused Honeycomb.

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Open ID authentication..

What is open ID ?

An OpenID is a way of identifying yourself no matter which web site you visit. It's like a driver's license for the entire Internet. But, it's even more than that because you can (if you want) associate information with your OpenID like your name and your e-mail address, and then you choose how much web sites get to see about you. This means that web sites that take advantage of OpenID won't bother you for the same information over and over again.

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