Interview questions

Android Interview Questions and Answers

1) What is Android?
It is an open-sourced operating system that is used primarily on mobile devices, such as cell phones and tablets. It is a Linux kernel-based system that’s been equipped with rich components that allows developers to create and run apps that can perform both basic and advanced functions.

2) What Is the Google Android SDK?

The Google Android SDK is a toolset that developers need in order to write apps on Android enabled devices. It contains a graphical interface that emulates an Android driven handheld environment, allowing them to test and debug their codes.

3) What is the Android Architecture?

Android Architecture is made up of 4 key components:
– Linux Kernel
– Libraries
– Android Framework
– Android Applications

4) Describe the Android Framework.

The Android Framework is an important aspect of the Android Architecture. Here you can find all the classes and methods that developers would need in order to write applications on the Android environment.

5) What is AAPT?

AAPT is short for Android Asset Packaging Tool. This tool provides developers with the ability to deal with zip-compatible archives, which includes creating, extracting as well as viewing its contents.

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Angular JS Interview Questions and Answers

1.What is AngularJS?

AngularJS is a javascript framework used for creating single web page applications.  It allows you to use HTML as your template language and enables you to extend HTML’s syntax to express your application’s components clearly

2.Explain what are the key features of AngularJS ?

The key features of AngularJS are

• Scope
• Controller
• Model
• View
• Services
• Data Binding
• Directives
• Filters
• Testable

3.Explain what is scope in AngularJS ?

Scope refers to the application model, it acts like glue between application controller and the view.  Scopes are arranged in hierarchical structure and impersonate the DOM ( Document Object Model) structure of the application.  It can watch expressions and propagate events.

4.Explain what is services in AngularJS ?

In AngularJS services are the singleton objects or functions that are used for carrying out specific tasks.  It holds some business logic and these function can be called as controllers, directive, filters and so on.

5.Explain what is Angular Expression? Explain what is key difference between angular expressions and JavaScript expressions?

Like JavaScript,  Angular expressions are code snippets that are usually placed in binding such as {{ expression }}

The key difference between the JavaScript expressions and Angular expressions

• Context :In Angular, the expressions are evaluated against a scope object, while the Javascript expressions are evaluated against the global window
• Forgiving:In Angular expression evaluation is forgiving to null and undefined, while in Javascript undefined properties generates TypeError or ReferenceError
• No Control Flow Statements:Loops, conditionals or exceptions cannot be used in an angular expression
• Filters:To format data before displaying it you can use filters

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AWS Interview Questions and Answers

1.What kind of network performance parameters can you expect when you launch instances in cluster placement group?
The network performance depends on the instance type and network performance specification, if launched in a placement group you can expect up to

• 10 Gbps in a single-flow,
• 20 Gbps in multiflow i.e full duplex
• Network traffic outside the placement group will be limited to 5 Gbps(full duplex).

2.To deploy a 4 node cluster of Hadoop in AWS which instance type can be used?

First let’s understand what actually happens in a Hadoop cluster, the Hadoop cluster follows a master slave concept. The master machine processes all the data, slave machines store the data and act as data nodes. Since all the storage happens at the slave, a higher capacity hard disk would be recommended and since master does all the processing, a higher RAM and a much better CPU is required. Therefore, you can select the configuration of your machine depending on your workload. For e.g. – In this case c4.8xlarge will be preferred for master machine whereas for slave machine we can select i2.large instance. If you don’t want to deal with configuring your instance and installing hadoop cluster manually, you can straight away launch an Amazon EMR (Elastic Map Reduce) instance which automatically configures the servers for you. You dump your data to be processed in S3, EMR picks it from there, processes it, and dumps it back into S3.

3.Where do you think an AMI fits, when you are designing an architecture for a solution?

AMIs(Amazon Machine Images) are like templates of virtual machines and an instance is derived from an AMI. AWS offers pre-baked AMIs which you can choose while you are launching an instance, some AMIs are not free, therefore can be bought from the AWS Marketplace. You can also choose to create your own custom AMI which would help you save space on AWS. For example if you don’t need a set of software on your installation, you can customize your AMI to do that. This makes it cost efficient, since you are removing the unwanted things.

4.How do you choose an Availability Zone?

Let’s understand this through an example, consider there’s a company which has user base in India as well as in the US.

Let us see how we will choose the region for this use case :

So, with reference to the above figure the regions to choose between are, Mumbai and North Virginia. Now let us first compare the pricing, you have hourly prices, which can be converted to your per month figure. Here North Virginia emerges as a winner. But, pricing cannot be the only parameter to consider. Performance should also be kept in mind hence, let’s look at latency as well. Latency basically is the time that a server takes to respond to your requests i.e the response time. North Virginia wins again!

So concluding, North Virginia should be chosen for this use case.

5.Is one Elastic IP address enough for every instance that I have running?

Depends! Every instance comes with its own private and public address. The private address is associated exclusively with the instance and is returned  to Amazon EC2 only when it is stopped or terminated. Similarly, the public address is associated exclusively with the instance until it is stopped or terminated. However, this can be replaced by the Elastic IP address, which stays with the instance as long as the user doesn’t manually detach it. But what if you are hosting multiple websites on your EC2 server, in that case you may require more than one Elastic IP address.

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Top 25 Data Science Interview Questions and Answers

1) How would you create a taxonomy to identify key customer trends in unstructured data?

The best way to approach this question is to mention that it is good to check with the business owner and understand their objectives before categorizing the data. Having done this, it is always good to follow an iterative approach by pulling new data samples and improving the model accordingly by validating it for accuracy by soliciting feedback from the stakeholders of the business. This helps ensure that your model is producing actionable results and improving over the time.

2) Python or R – Which one would you prefer for text analytics?

The best possible answer for this would be Python because it has Pandas library that provides easy to use data structures and high performance data analysis tools.

3) Which technique is used to predict categorical responses?

Classification technique is used widely in mining for classifying data sets.

4) What is logistic regression? Or State an example when you have used logistic regression recently.

Logistic Regression often referred as logit model is a technique to predict the binary outcome from a linear combination of predictor variables. For example, if you want to predict whether a particular political leader will win the election or not. In this case, the outcome of prediction is binary i.e. 0 or 1 (Win/Lose). The predictor variables here would be the amount of money spent for election campaigning of a particular candidate, the amount of time spent in campaigning, etc.

5) What are Recommender Systems?

A subclass of information filtering systems that are meant to predict the preferences or ratings that a user would give to a product. Recommender systems are widely used in movies, news, research articles, products, social tags, music, etc.

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Python Flask Interview Questions ans Answers

Q1). What is Flask?

Ans1: Flask is a web micro framework for Python based on “Werkzeug, Jinja 2 and good intentions” BSD licensed. Werkzeug and jingja are two of its dependencies.

Q2). What is the benefit of using Flask?

Ans2: Flask is part of the micro-framework. Which means it will have little to no dependencies on external libraries. It makes the framework light while there is little dependency to update and less security bugs.

Q3). What is the difference between Django, Pyramid, and Flask?

Ans3: Flask is a “microframework” primarily build for a small application with simpler requirements. In flask, you have to use external libraries. Flask is ready to use.Pyramid are build for larger applications. It provides flexibility and lets the developer use the right tools for their project. The developer can choose the database, URL structure, templating style and more. Pyramid is heavy configurable.

Q4). What is Flask-WTF and what are their features?

Ans4: Flask-WTF offers simple integration with WTForms. Features include for Flask WTF are

• Integration with wtforms
• Secure form with csrf token
• Global csrf protection
• Internationalization integration
• Recaptcha supporting
• File upload that works with Flask Uploads

Q5). What is the common way for the Flask script to work?

Ans5: The common way for the flask script to work is

• Either it should be the import path for your application
• Or the path to a Python file

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Swift Programming Interview Questions

1) Explain what is Swift Programming Language?

Swift is a programming language and system for creating applications for iOS and OS X. It is an innovative programming language for Cocoa and Cocoa Touch.

2) Explain how you define variables in Swift language?

Variables and constants must be declared before they are used. You announce constants with the let keyword and variables with the var keyword. Both variables and dictionaries are described using brackets. For example,

Var  myTectra = “This is myTectra”

Let ksomeconstant = 30

3) Explain how Swift program is deployed?

Swift program deploys the application in a Tomcat installation by default. The deploy script bundles the client code into JavaScript, gathers all the server side classes required and packages them into file Hello.war. This file together with a GWT jar and a Swift runtime jar is copied into the Tomcat installation. If CATALINA_HOME is not set, these files require to be copied manually.

4) Mention what are the features of Swift Programming?

• It eliminates entire classes of unsafe code
• Variables are always initialized before use
• Arrays and integers are checked for overflow
• Memory is managed automatically
• Instead of using “if” statement in conditional programming, swift has “switch” function

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Tableau Interview Question and Answers

1.What is Data Visualization?

A much advanced, direct, precise and ordered way of viewing large volumes of data is called data visualization. It is the visual representation of data in the form of graphs and charts, especially when you can’t define it textually. You can show trends, patters and correlations through various data visualization software and tools; Tableau is one such data visualization software used by businesses and corporates.

2.What are the differences between Tableau desktop and Tableau Server?

While Tableau desktop performs data visualization and workbook creation, Tableau server is used to distribute these interactive workbooks and/or reports to the right audience. Users can edit and update the workbooks and dashboards online or Server but cannot create new ones. However, there are limited editing options when compared to desktop.
Tableau Public is again a free tool consisting of Desktop and Server components accessible to anyone.

3.Define parameters in Tableau and their working.

Tableau parameters are dynamic variables/values that replace the constant values in data calculations and filters. For instance, you can create a calculated field value returning true when the score is greater than 80, and otherwise false. Using parameters, one can replace the constant value of 80 and control it dynamically in the formula.

4.Define parameters in Tableau and their working.

Tableau parameters are dynamic variables/values that replace the constant values in data calculations and filters. For instance, you can create a calculated field value returning true when the score is greater than 80, and otherwise false. Using parameters, one can replace the constant value of 80 and control it dynamically in the formula.

5.Differentiate between parameters and filters in Tableau.

The difference actually lies in the application. Parameters allow users to insert their values, which can be integers, float, date, string that can be used in calculations. However, filters receive only values users choose to ‘filter by’ the list, which cannot be used to perform calculations.
Users can dynamically change measures and dimensions in parameter but filters do not approve of this feature.Most in-depth, industry-led curriculum in Tableau.

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Data Science With Python Interview Questions and Answers

Q1). How can you build a simple logistic regression model in Python?

Q2). How can you train and interpret a linear regression model in SciKit learn?

Q3).Name a few libraries in Python used for Data Analysis and Scientific computations.

Ans1.2.3: NumPy, SciPy, Pandas, SciKit, Matplotlib, Seaborn

Q4).Which library would you prefer for plotting in Python language: Seaborn or Matplotlib?

Ans4: Matplotlib is the python library used for plotting but it needs lot of fine-tuning to ensure that the plots look shiny. Seaborn helps data scientists create statistically and aesthetically appealing meaningful plots. The answer to this question varies based on the requirements for plotting data.

Q5).What is the main difference between a Pandas series and a single-column DataFrame in Python?

Q6). Write code to sort a DataFrame in Python in descending order.

Q7). How can you handle duplicate values in a dataset for a variable in Python?

Q8). Which Random Forest parameters can be tuned to enhance the predictive power of the model?

Q9). Which method in pandas.tools.plotting is used to create scatter plot matrix?

Ans5.6.7.8.9: Scatter_matrix

Q10). How can you check if a data set or time series is Random?

Ans10: To check whether a dataset is random or not use the lag plot. If the lag plot for the given dataset does not show any structure then it is random.

Q 11).Can we create a DataFrame with multiple data types in Python? If yes, how can you do it?

  Q12). Is it possible to plot histogram in Pandas without calling Matplotlib? If yes, then write the code to plot the histogram?

 Q13). What are the possible ways to load an array from a text data file in Python? How can the efficiency of the code to load data file be improved?

 Ans11.12.13: numpy.loadtxt ()

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Magento Interview Questions

1.What is Magento?

A:Magento is an open source E-commerce software, created by Varien which is useful for online business and it has the flexible modular architecture. It is scalable and it has many control options that helps the user. Magento uses E-commerce platform which offers companies ultimate E-commerce solutions and extensive support network.

2.Why to use Magento?

A:The uses of Magento are:

• Magento is open source E-commerce software.
• It is scalable and offers small companies to build business.
• It provides the searching and sorting of products in several ways.
• Easily integrates with many of the third-party sites which are needed to run effective E-commerce website.
• Using this, customer can order or purchase number of products. There are no limits on number of purchasing products.

3.List the Web-Hosting sites of Magento?

A:The Web-Hosting sites of Magento are:

• SiteGround
• BlueHost
• HostGator
• Inmotion
• Arvixe
• site5

4.What are disadvantages of Magento?

A:The disadvantages of Magento are:

• Magento uses larger disk space and memory.
• It takes much time to build the customized functionality.
• It is very slow compared to other E-commerce sites.
• It needs proper hosting environment, if the hosting environment is improper the user can face the problems.

5.Name the web-server that supports Magento?

A:The Web-server that supports Magento are:

• Apache 2.x
• Nginx 1.7.x

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Devops Interview Questions and Answers

1.Explain what is DevOps?

It is a newly emerging term in IT field, which is nothing but a practice that emphasizes the collaboration and communication of both software developers and other information-technology (IT) professionals. It focuses on delivering software product faster and lowering the failure rate of releases.

2.List the essential tools used in Devops.

• Git
• Jenkins
• Selenium
• Puppet
• Chef
• Ansible
• Nagios
• Docker
• Monit
• ELK –Elasticsearch, Logstash, Kibana
• Collectd/Collect
• Git(GitHub)

3.What are the core operations of DevOps in terms of development and Infrastructure?

The core operations of DevOps

• Application development
• Code developing
• Code coverage
• Unit testing
• Packaging
• Deployment With infrastructure
• Provisioning
• Configuration
• Orchestration
• Deployment

4. What are the advantages of DevOps with respect to Technical and Business perspective?

Technical benefits:

• Software delivery is continuous.
• Reduces Complexity in problems.
• Faster approach to resolve problems
• Manpower is reduced.

Business benefits:

• High rate of delivering its features
• Stable operating environments
• More time gained to Add values.
• Enabling faster feature time to market

5. The scope for SSH?

• SSH is a Secure Shell which provides users with a secure, encrypted mechanism to log into systems and transfer files.
• To log out a remote machine and work on command line.
• To secure encrypted communications between two hosts over an insecure network.

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Real Time Questions and Answers for Digital Marketing Interview

Q: 1 What is digital marketing?

Ans: Digital marketing (also known as data-driven marketing) is an umbrella term for the marketing of products or services using digital technologies, mainly on the Internet, but also including mobile phones, display advertising, and any other digital medium. The key objective is to promote brands and increase sales through various digital marketing techniques.

Q:2 What are the various digital marketing marketing techniques?

Ans: Various digital marketing techniques are-

• Search engine optimization (SEO)
• Search engine marketing (SEM)
• Social media marketing
• Email marketing
• Content marketing
• PPC (Pay per click marketing)
• Compaign marketing
• Display advertising
• e-books
• Influencer marketing

Q:3 How can you categorize the digital marketing?

Ans : The digital marketing/communication is categorized into two segments

Inbound Marketing: This techniques takes the help of social media, digital content in e-books, webinars or e-newsletter for attracting the attention of prospects via content creation to increase the number of clicks on links and learn more about a company and its services.

Outbound Marketing: This segment includes placing ads, cold-calls, e-mails or reach out potential customers through digital mediums.

Q:4 Why is online marketing preferred over offline marketing?

Ans: Currently online marketing preferred by many businesses mainly because we are living in the digital era.

• Online marketing allows you to reach a large number of people and create brand awareness
• Technically online marketing is less expensive in terms of applying aggressive promotional strategies.
• No need to bother about printing, painting. Fabrication, rents, offline execution, negotiation etc.
• Ability to target specific audiences from specific locations with ease.
• ROI based marketing is now available.
• One can reach many individuals online and you can set your target as worldwide.

Whereas the number of people who prefer reading newspapers, watching television, etc. Therefore, the target is within a specific area.

 Q5) What is the most effective way to increase the traffic to your website?

Ans: Various ways to increase the traffic to your website –

• Advertise. This one is so obvious, we’re going to look at it first. …
• Get Social. …
• Mix It Up. …
• Write Irresistible Headlines. …
• Pay Attention to On-Page SEO. …
• Target Long-Tail Keywords. …
• Site should be responsive. …
• Invite Others to Guest Blog on Your Site
• Link internally
• Make yourself heard in comment section
• Get active on social media

   Q6)However, the most important factor is to focus on User Retention.

In reality, there are very few visitors that convert and become consistent visitors of your website. But if one focuses on retaining users, you will exceed those thousands of visits in a couple of months. By focusing on user retention, you can build a site where people will keep coming back to it.

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Django Interview Questions and Answers

Q1).Explain what is Django?

Ans1: Django is a web framework in python to develop a web application in python.

Django is a free and open source web application framework, written in Python.

Q2).Mention what are the features available in Django?

Ans2: Features available in Django are

• Admin Interface (CRUD)
• Templating
• Form handling
• Internationalization
• Session, user management, role-based permissions
• Object-relational mapping (ORM)
• Testing Framework
• Fantastic Documentation

Q3).Mention the architecture of Django architecture?

Ans3: Django architecture consists of

• Models: It describes your database schema and your data structure
• Views: It controls what a user sees, the view retrieves data from appropriate models and execute any calculation made to the data and pass it to the template
• Templates: It determines how the user sees it. It describes how the data received from the views should be changed or formatted for display on the page
• Controller: The Django framework and URL parsing

Q4).Why Django should be used for web-development?

Ans4:

• It allows you to divide code modules into logical groups to make it flexible to change
• To ease the website administration, it provides auto-generated web admin
• It provides pre-packaged API for common user tasks
• It gives you template system to define HTML template for your web page to avoid code duplication
• It enables you to define what URL be for a given function
• It enables you to separate business logic from the HTML
• Everything is in python

Q5). Explain how you can create a project in Django?

Ans5: To start a project in Django, you use command $ django-admin.py and then use the command

Project

_init_.py

manage.py

settings.py

urls.py

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Ext JS Interview Questions

1.Why we need javascript Library?

Javascript is an awesome language. It’s super flexible.Browsers are the modern UI paradigm.
The javascript Libraries now must provide a rich set of UI Widgets.
javascript libraries:

• JQuery
•  Qooxdoo
•  Dojo
• Prototype.js
• mootools
• extjs

2. Why did you choose Ext JS?

The overall design of extjs is exemplary.One can learn a lot from it’s unified architecture – no matter which language one is programming in.
Extjs requires you to start with one of their base classes – ensuring a consitent model. Consistency is extremely important for the library to be reusable.
a.Extjs documentation seems to be very comprehensive and well maintained.
b.key aspect of the EXTJS Library is the cross-browser support.
c.Build rich Internet applications with Ext JS
d. Ext JS framework is the multitude of rich UI elements provided. These elements include forms, dialog boxes, tabs, trees, and grids.
e.The Ext JS framework includes support for Ajax implementations.
f.Ext JS integration with other Web server frameworks.
g.Ext JS framework development into several popular integrated development environments (IDEs), including Eclipse, Aptana, and Komodo.
h.Ext JS provides excellent performance.The framework is fully object oriented and extensible. Because it’s written in the JavaScript language

3. What are major Web browsers supported by Ext JS framework?

• Windows® Internet Explorer® version 6 and later.
• Mozilla Firefox version 1.5 and later (PC and Macintosh).
•  Apple Safari version 2 and later.
•  Opera version 9 and later (PC and Mac).

4. Integration of Web development server-side frameworks with Ext JS?
You can use Ext JS with other common Web development server-side frameworks, including PHP, the Java™ language, Microsoft® .NET, Ruby on Rails, and ColdFusion.

5. Where Extjs extended from ?
Ext JS as a project to extend the functionality that the YUI Library.A key aspect of the YUI Library is the cross-browser support.The Extjs framework is fully object oriented and extensible. Because it’s written in the JavaScript language.

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IOS interview questions and answers

1 . What is a memory leak?

A memory leak is a type of resource leak that occurs when a computer program incorrectly manages memory allocations in such a way that memory which is no longer needed is not released. In object-oriented programming, a memory leak may happen when an object is stored in memory but cannot be accessed by the running code.

2 .Describe what “app thinning” means ?

The store and operating system optimize the installation of iOS, tvOS, and watchOS apps by tailoring app delivery to the capabilities of the user’s particular device, with minimal footprint. This optimization, called app thinning, lets you create apps that use the most device features, occupy minimum disk space, and accommodate future updates that can be applied by Apple.

3. What is auto-layout?

Auto Layout dynamically calculates the size and position of all the views in your view hierarchy, based on constraints placed on those views.

4 .What is GCD? How is it used?

GCD is the most commonly used API to manage concurrent code and execute operations asynchronously at the Unix level of the system. GCD provides and manages queues of tasks. A good example is when an App fetch data from an API, this network call should be done in a background thread and the display of the data in the view should be executed in the main thread as well as any UI updates.

5 .What are the benefits of Swift over Objective-C ?

• Swift is easier to read. (mmm really?)
• Swift is easier to maintain.
• Swift is safer.
• Swift is unified with memory management.
• Swift requires less code.
• Swift is faster.
• Fewer name collisions with open source projects.
• Swift support dynamic libraries.
• Swift Playgrounds encourages interactive coding.
• Swift is a future you can influence.

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Node JS Interview Questions

1)      What is node.js?

Node.js is a Server side scripting which is used to build scalable programs. Its multiple advantages over other server side languages, the prominent being non-blocking I/O.

2)      Where can we use node.js?

Node.js can be used for the following purposes

1. a)      Web applications ( especially real-time web apps )
2. b)      Network applications
3. c)       Distributed systems
4. d)      General purpose applications

3)      What is the advantage of using node.js?

1. a)      It provides an easy way to build scalable network programs
2. b)      Generally fast
3. c)       Great concurrency
4. d)      Asynchronous everything
5. e)      Almost never blocks

4)      What are the two types of API functions in Node.js ?

The two types of API functions in Node.js are

1. a)      Asynchronous, non-blocking functions
2. b)      Synchronous, blocking functions

5)      What is control flow function?

A generic piece of code which runs in between several asynchronous function calls is known as control flow function.

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Oracle SCM Interview Questions

 1.Control Options in Inventory

Lot Control , Locator control, serial control, revision control, locator & sub inventory restrictions.

2. Trip ?

Trip is a carrier specific and contains atleast two stop such as stop to pick up goods and deliver goods.

3.What is the difference between ‘Accrue On Receipt’ and ‘Accrue at Period End’?

Accrue On Receipt means that when a receipt is saved, accrual transactions are immediately recorded and sent to the general ledger interface. This is also known as “online” accruals. Accrue at Period End means that when a receipt is saved, the accrual transactions are not immediately recorded and sent to the general ledger; instead, the accounting entries are generated and sent at the end of the month by running the Receipt Accruals – Period-End Process.
All items with a destination type of either Inventory and Outside Processing are accrued on receipt. For items with a destination type of Expense, you have the option of accruing on receipt or at period end.

4.Why are expense items typically accrued at period-end, and why are inventory

items always accrued on receipt?

One should accrue on receipt if perpetual inventory is adopted to facilitate reconciliation between inventory valuation reports and accounting entries. Expense items typically are not accounted for on a daily basis, and most companies find it easier to account for and reconcile these expenses at month-end rather than at the time each individual expense is incurred.

When both inventory and expense items are accrued on receipt, the following problems may be encountered:
A) Receiving inspection balances will include both inventory assets and expenses, so at the end of the month, they will need to be manually reclassified.
B) The number of entries needed to research and reconcile the perpetual A/P Accrual Account(s) becomes significantly increased. Since the expense receipts could double the number of accrual accounting entries to process, the Accrual Reconciliation Report could take twice as long to run. The amount of time required by your staff to research any discrepancies would also increase.

5.What is the significance of the Document Total and Account Range types on the Approval Groups form?

The Document Total type sets the maximum limit for any approval actions taken by the user whom the approval group applies to. If multiple Document Totals are specified, the restriction will be to the Document Total, which is the lowest. The Account Range also allows for a document total which is then tied to a specific range of accounts listed on the same line. It is possible to have different account ranges with different amount Limits. This allows the same user to have a different dollar/account limit. It is mandatory to have an account range specified in each approval group defined. By default, if there is not an account range defined, all accounts will then be excluded from the document approval process, which means that the documents will not have an ability to become approved.

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Pentaho BI Interview Question and Answers

1.Define Pentaho and its usage.

Revered as one of the most efficient and resourceful data integration tools (DI),  Pentaho  virtually supports all available data sources and allows scalable data clustering and data mining. It is a light-weight Business Intelligence suite executing Online Analytical Processing (OLAP) services, ETL functions, reports and dashboards creation and other data-analysis and visualization operations.

2.Explain the important features of Pentaho.

• Pentaho is capable of creating Advanced Reporting Algorithms regardless of their input and output data format.
• It supports various report formats, whether Excel spreadsheets, XMLs, PDF docs, CSV files.
• It is a Professionally Certified DI Software rendered by the renowned Pentaho Company headquartered in Florida, United States.
• Offers enhanced functionality and in-Hadoop functionality.
• Allows dynamic drill down into larger and greater information.
• Rapid Interactive response optimization.
• Explore and view multidimensional data.

3. Name major applications comprising Pentaho BI Project.

• Business Intelligence Platform.
• Dashboards and Visualizations.
• Data Mining.
• Data Analysis.
• Data Integration and ETL (also called Kettle).
• Data Discovery and Analysis (OLAP).

4. What is the importance of metadata in Pentaho?

A metadata model in Pentaho formulates the physical structure of your database into a logical business model. These mappings are stored in a central repository and allow developers and administrators to build business-logical DB tables that are cost effective and optimized. It further simplifies the working of business users allowing them to create formatted reports and dashboards ensuring security to data access.
All in all, metadata model provides an encapsulation around the physical definitions of your database and the logical representation and define relationships between them.

5.Define Pentaho Reporting Evaluation.

Pentaho Reporting Evaluation is a particular package of a subset of the Pentaho Reporting capabilities, designed for typical first-phase evaluation activities such as accessing sample data, creating and editing reports, and viewing and interacting with reports.

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Top 25 Python Interview Questions and Answers Prepared by Experts

1. What is JSON? How would convert JSON data into Python data?

JSON – stands for JavaScript Object Notation. It is a popular data format for storing data in NoSQL
databases. Generally JSON is built on 2 structures.

1.  A collection of <name, value> pairs.
2.  An ordered list of values.
   As Python supports JSON parsers, JSON-based data is actually represented as a dictionary in Python. You can convert json data into python using load() of json module.

2. How are the functions help() and dir() different?

These are the two functions that are accessible from the Python Interpreter. These two functions are used for viewing a consolidated dump of built-in functions.

• help() – it will display the documentation string. It is used to see the help related to modules, keywords, attributes, etc.
  To view the help related to string datatype, just execute a statement help(str) – it will display the documentation for ‘str, module. ◦ Eg: >>>help(str) or >>>help() – it will open the prompt for help as help>
• to view the help for a module, help> module module name Inorder to view the documentation of ‘str’ at the help>, type help>modules str
• to view the help for a keyword, topics, you just need to type, help> “keywords python- keyword” and “topics list”
• dir() – will display the defined symbols. Eg: >>>dir(str) – will only display the defined symbols.

3. Which command do you use to exit help window or help command prompt?

quit
When you type quit at the help’s command prompt, python shell prompt will appear by closing the help window automatically.

4. Does the functions help() and dir() list the names of all the built_in functions and variables? If no, how would you list them?

No. Built-in functions such as max(), min(), filter(), map(), etc is not apparent immediately as they are
available as part of standard module.To view them, we can pass the module ” builtins ” as an argument to “dir()”. It will display the
built-in functions, exceptions, and other objects as a list.>>>dir(__builtins )
[‘ArithmeticError’, ‘AssertionError’, ‘AttributeError’, ……… ]

5. Explain how Python does Compile-time and Run-time code checking?

Python performs some amount of compile-time checking, but most of the checks such as type, name, etc are postponed until code execution. Consequently, if the Python code references a user -defined function that does not exist, the code will compile successfully. In fact, the code will fail with an exception only when the code execution path references the function which does not exists.

>>Read more >>

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Top 25 Hadoop Interview Questions Prepared by Experts

1)    What are real-time industry applications of Hadoop?

Hadoop, well known as Apache Hadoop, is an open-source software platform for scalable and distributed computing of large volumes of data. It provides rapid, high performance and cost-effective analysis of structured and unstructured data generated on digital platforms and within the enterprise. It is used in almost all departments and sectors today.Some of the instances where Hadoop is used:

• Managing traffic on streets.
• Streaming processing.
• Content Management and Archiving Emails.
• Processing Rat Brain Neuronal Signals using a Hadoop Computing Cluster.
• Fraud detection and Prevention.
• Advertisements Targeting Platforms are using Hadoop to capture and analyze click stream, transaction, video and social media data.
• Managing content, posts, images and videos on social media platforms.
• Analyzing customer data in real-time for improving business performance.
• Public sector fields such as intelligence, defense, cyber security and scientific research.
• Financial agencies are using Big Data Hadoop to reduce risk, analyze fraud patterns, identify rogue traders, more precisely target their marketing campaigns based on customer segmentation, and improve customer satisfaction.
• Getting access to unstructured data like output from medical devices, doctor’s notes, lab results, imaging reports, medical correspondence, clinical data, and financial data.

2) Compare Hadoop & Spark

Criteria                                           Hadoop                                                   Spark

Dedicated storage                           HDFS                                                     None

Speed of processing                        average                                                excellent

Libraries                                        Separate tools available                        Spark Core, SQL, Streaming, MLlib, GraphX

3)    How is Hadoop different from other parallel computing systems?

Hadoop is a distributed file system, which lets you store and handle massive amount of data on a cloud of machines, handling data redundancy. The primary benefit is that since data is stored in several nodes, it is better to process it in distributed manner. Each node can process the data stored on it instead of spending time in moving it over the network.

On the contrary, in Relational database computing system, you can query data in real-time, but it is not efficient to store data in tables, records and columns when the data is huge.

Hadoop also provides a scheme to build a Column Database with Hadoop HBase, for runtime queries on rows.

>> Read more >>

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Top 25 PowerShell Interview Questions Prepared by Experts

1)   Explain what is PowerShell?

Power shell is an extendable command shell and a scripting language for Windows.

2)   What are the key characteristics of PowerShell?

The key characteristics of PowerShell are

• PowerShell is object-based and not text based
• Commands in PowerShell are customizable
• It is a command line interpreter and scripting environment

3)   In PowerShell what does variables holds?

In variables PowerShell contains strings, integers and objects.  It does not have special variables as it is pre-defined with PowerShell

4)   Explain what is the significance of brackets in PowerShell?

• Parenthesis Brackets (): Curved parenthesis style brackets are used for compulsory arguments.

• Braces Brackets {} : Curly brackets are employed in blocked statements

• Square Brackets []: They define optional items, and they are not frequently used

5)   What does it mean cmdlet’s?

Cmdlet’s are simple build in commands written in .net language like C# or VB introduced by Windows PowerShell.

6)    Explain what is PowerShell Loop?

Automating repetitive task with the help of PowerShell loop is known as PowerShell Loop.  Through PowerShell, you can execute  For each loop,  While loop  and Do While loop.

>>Read more >>

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Top 70 Seo Interview Questions and Answers 2017 | myTectra.com

Questions and Answers for Beginners or Freshers Candidates:

Q1). What do you understand by the term “SEO” and introduce its types?

Ans1: SEO is an abbreviated which stands for “Search Engine Optimization”. It is a technique through which you can easily increase the visibility of your website or the web page in the SERP’s (search engine result pages) or unpaid results—often referred to as “organic”, “natural”, or “earned” results.

The two types of SEO are:

1. On Page Optimization.
2. Off Page Optimization.

Q2). What are the SEO tools do you use?

Ans2: Some of the SEO tools that you can use are Google analytic, keyword search, Alexa, open site explorer, Google Webmaster.

Q3). What will you do to make a website search engine friendly?

Ans3: There are few things that you should keep in mind to make a website search engine friendly are word count, backlinks,  anchor text, outbound links, keyword etc.

Q4). What do you mean by Backlink and mention its importance in SEO?

Ans4: Backlink is basically referred as incoming links to your website or web page. It is important because it results in the better chance of visibility in the search engine along with better traffic and ranking.

Q5). Why is SEO so important?

Ans5: The Search engine optimization (SEO) is essential because of the following reasons:-

Most of the user’s majority of search engines is more likely to click on one of the top 5 suggestions on the results pages (SERPS), so to take advantage of this and gain visitors to your website or customers to your online store you need to in the top positions.

>>Read more >>

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Python real time Interview Questions and Answers

Q1).What is Python?
Ans1: Python is a high-level, interpreted, interactive and object-oriented scripting language. Python is designed to be highly readable. It uses English keywords frequently where as other languages use punctuation, and it h
as fewer syntactical constructions than other languages.

Q2).Name some of the features of Python.
Ans2: Following are some of the salient features of python −

• It supports functional and structured programming methods as well as OOP.
• It can be used as a scripting language or can be compiled to byte-code for building large applications.
• It provides very high-level dynamic data types and supports dynamic type checking.
• It supports automatic garbage collection.
• It can be easily integrated with C, C++, COM, ActiveX, CORBA, and Java.

Q3).Do you have any personal projects?
Really?
Ans3:This shows that you are willing to do more than the bare minimum in terms of keeping your skillset up to date. If you work on personal projects and code outside of the workplace then employers are more likely to see you as an asset that will grow. Even if they don’t ask this question I find it’s useful to broach the subject.

Q4).Is python a case sensitive language?
Ans4: Yes! Python is a case sensitive programming language.

What are the supported data types in Python?
Python has five standard data types −

• Numbers
• String
• List
• Tuple
• Dictionary 

Q5).What is the output of print str if str = ‘Hello World!’?
Ans5: It will print complete string. Output would be Hello World!.

>>Read more>>

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Hive Interview Questions and Answers

1) Explain what is Hive?

Hive is an ETL and Data warehousing tool developed on top of Hadoop Distributed File System (HDFS). It is a data warehouse framework for querying and analysis of data that is stored in HDFS. Hive is an open-source-software that lets programmers analyze large data sets on Hadoop.

2) When to use Hive?

• Hive is useful when making data warehouse applications
• When you are dealing with static data instead of dynamic data
• When application is on high latency (high response time)
• When a large data set is maintained
• When we are using queries instead of scripting

3) Mention what are the different modes of Hive?

Depending on the size of data nodes in Hadoop, Hive can operate in two modes.

These modes are,

• Local mode
• Map reduce mode

4) Mention when to use Map reduce mode?

Map reduce mode is used when,

• It will perform on large amount of data sets and query going to execute in a parallel way
• Hadoop has multiple data nodes, and data is distributed across different node we use Hive in this mode
• Processing large data sets with better performance needs to be achieved

5) Mention key components of Hive Architecture?

Key components of Hive Architecture includes,

• User Interface
• Compiler
• Metastore
• Driver
• Execute Engine

>>Read more >>

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Web Design Interview Questions and Answers

1.Mention what are the main language or platform used for web-design?

The main language used for web-designing are

• HTML: Base template
• CSS: Styling
• JavaScript: Functionality
• PHP: Server side scripts

2.Explain how can you set an image as a background on web pages?

To set an image as a background on web page, point the body background to the name of your image you want to set as a background as shown below.

</head>tag.

<body background= “picture.gif”>

You can also fix the background image, so while using the scroll bar in the browser, it does not move.  To do this add the BGPROPERTIES tag as shown below
<body background = “picture.gif”bgproperties=”fixed”>

3.Mention what do you mean by Responsive design on a web page?

Responsive design is an approach to building sites to provide an optimal viewing and interaction experience. It focuses on easy navigation of site with a minimum of scrolling, panning and resizing across all devices.

Bootstrap is the most popular CSS, HTML and JS framework used for developing responsive web design

4.Mention what are some bad examples of web design?

• Blinking, spinning or flashing images
• Black background with white, light or pale text
• Black backgrounds with dark text
• Busy tiled background images with any color text
• Everything Centered
• Too many images or Huge images
• List of links
• Too many headlines or Blinking text

5.Explain what is Information Architecture?

On web page information, architecture is often referred to the structure and navigation of an entire site.

>>Read more>>

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Automation Testing Python Interview Questions

1.What is Python? What are the benefits of using Python?

Answer:Python is a programming language with objects, modules, threads, exceptions and automatic memory management. The benefits of pythons are that it is simple and easy, portable, extensible, build-in data structure and it is an open source.

2. How Python can be used in software testing? 

Answer:
1. To generate test data; parse test results; generate reports; testing API calls etc.
2. Python to extract requirements from a Word document.
3. For testing tasks automation, setting up environments for tests, extracting performance data, etc…
4. Testers use Python extensively in many companies with Selenium for test automation.
5. For writing desktop applications used by testers.
6. Test data manipulation.
7. To build test environment
8. Testing with IronPython on .NET

3.What Python frameworks do you know? 

Answer: Framework called Web2py, PAMIE (Python automation Module for I. E.), The py.test framework

4.Question:What tools that helps Python development do you know?

 Answer:There are good tools for helping Python development such as Notepad++ with the PyNPP plugin and Eclipse with PyDev and PyUnit.

5. The following is displayed by a print function call: 
yesterday today tomorrow Please write an example of a print function.

Answer: print(‘yesterday\ntoday\ntomorrow’)

>>Read more>>

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Ruby on Rails Interview Questions

1) Explain what is Ruby on Rails?

• Ruby:It is an object oriented programming language inspired by PERL and PYTHON.
• Rails:It is a framework used for building web application

2) Explain what is class libraries in Ruby?

Class libraries in Ruby consist of a variety of domains, such as data types, thread programming, various domains, etc.

3) Mention what is the naming convention in Rails?

• Variables:For declaring Variables, all letters are lowercase, and words are separated by underscores
• Class and Module: Modules and Classes uses MixedCase and have no underscore; each word starts with a uppercase letter
• Database Table: The database table name should have lowercase letters and underscore between words, and all table names should be in the plural form for example invoice_items
• Model: It is represented by unbroken MixedCase and always have singular with the table name
• Controller: Controller class names are represented in plural form, such that OrdersController would be the controller for the order table.

4) Explain what is “Yield” in Ruby on Rails?

A Ruby method that receives a code block invokes it by calling it with the “Yield”.

5) Explain what is ORM (Object-Relationship-Model) in Rails?

ORM or Object Relationship Model in Rails indicate that your classes are mapped to the table in the database, and objects are directly mapped to the rows in the table.

>>Read more>>

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Zend Framework Interview Questions

1.What is a Framework?

In software development, a framework is a defined support structure in which another software project can be organized and developed.

• An abstract design
•  Set of common functionality
•  Developed for a particular domain

 2.How to disable layout from controller?

$this->_helper->layout()->disableLayout();

Disable Zend Layout from controller for Ajax call only
if($this->getRequest()->isXmlHttpRequest()){

$this->_helper->layout()->disableLayout();

}

3.How to change the View render file from controller?
function listAction(){

//call another view file file

$this->render(“anotherViewFile”);

}

4.How to protect your site from sql injection in zend when using select query?
$select = $this->select()

from(array(‘u’ => ‘users’), array(‘id’, ‘username’))

where(‘name like ?’,”%php%”)

where(‘user_id=?’,’5′)

where(‘rating<=?’,10);

5.How to check post method in zend framework?
if($this->getRequest()->isPost()){

//Post

}else{

//Not post

}

>>Read more>>

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Ruby Cucumber Interview Questions

1.Define what is Cucumber?

Cucumber is a Behavior Driven Development (BDD) tool. Cucumber is a tool that executes plain-text functional descriptions as automated tests. The language that Cucumber understands is called Gherkin.

In BDD, users (business analysts, product owners) first write scenarios or acceptance tests that describes the behavior of the system from the customer’s perspective, for review and sign-off by the product owners before developers write their codes.

2.Cucumber execution starts from where ?

Cucumber execution will starts from support. In support first it will load the env.rb file then it will load hooks.rb and then it will start execute feature file scenario steps.

3.Define what is support, env.rb and hooks.rb ?

• Support is a foder where we can setup cucumber related support.
• rb file will be used to load the required libraries for cucumber scenario execution
• rb we will add hooks like before, after, beforeStep and afterStep hooks

4.Define what is profile in cucumber ?

• We can create Cucumber profiles to run specific features and step definitions
• We can use following command to execute a cucumber profile
• cucumber features -p <profile_name>

Ex: cucumber features -p regression
5. Define what are before, after, beforeStep and afterStep hooks?

• Before:execute before the feature file execution
• After:executes after the feature file execution
• BeforeStep:executes before the each step execution
• AfterStep:executes after the each step execution

>>Read more>>

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Typo3 CMS Interview Questions

1.What is TYPO3 CMS?

Answer:TYPO3 is a free and open source web content management system written in PHP. It is released under the GNU General Public License. It can run on several web servers, such as Apache or IIS, on top of many operating systems, among them Linux, Microsoft Windows, FreeBSD, Mac OS X and OS/2

2. What are the page-related functions in the context menu of a page?

Answer: The page-related functions in the context menu of a page are:

1. Show: Opens the page you clicked in the browser (frontend)
2. Disable: Disables the page (so it isn’t accessible from the frontend anymore)
3. Edit: Lets you edit the page properties
4. Info: Displays information about the page
5. History/Undo: Shows the change history of the page (who did which changes when)
6. Page Actions: Action related to the selected page
New: Lets you create a new page or new content
Cut: Cuts the page
Copy: Copies the page
Delete: Deletes the page
7. Branch Actions: Actions related to the whole branch
Mount as treeroot: Temporarily makes the selected page being the treeroot
Expand Branch: Same as clicking on a “closed” the arrow
Collapse Branch: Same as clicking on an “open” arrow
Export to .t3d: Opens the export tool and preselects the selected page
Import from .t3d: Opens the import tool and preselects the selected page

3. What is pid?

Answer: pid refers to the page the content element is on and it is one of the tt_content table field.

4.What is DB Mounts?

Answer: DB mounts (database mounts) are used to restrict a user’s access to only some parts of the page tree. Each mount corresponds to a page in the tree. The user will have access only to those pages and their sub- pages.

5. What is Database (DB) Check module?

Answer: Database (DB) Check module offers following four functions:

1. Record Statistics: Simple shows a count of the various records in the database, broken down by type for pages and content elements.

2. Relations: Checks if some relations are empty or broken, especially with regards to files.

3. Search: A tool to seach through the whole database. It offers an advanced mode which is nearly a visual query builder.

4. Check and update global reference index: TYPO3 CMS keeps a record of relations between all records. This may get out of sync when some operations are performed without the strict context of the backend. It is therefore useful to update this index regularly.

>>Read more>>

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TCL Interview Questions and Answers

1Q).What is TCL?
Ans1: Tcl (Tool Command Language) is a very powerful but easy to learn dynamic programming language, suitable for a very wide range of uses, including web and desktop applications, networking, administration, testing and many more. Open source and business-friendly, Tcl is a mature yet evolving language that is truly cross platform (windows,all flavors of linux,macintosh), easily deployed and highly extensible.

Q 2). How TCL Works?

Ans2: Tcl takes the Argument as a file and try to read the file. TCL stores the file in memory and reads the file Line by Line and try to validate/compile. TCL provides the output and release the memory.

Q3).how to increment eacl element in a list? eg: incrlist {1 2 3} =>2 3 4

Ans3: // it works like incrlist 5 6 7 =>> 6 7 8
proc incrlist args {
set s 0
foreach s $args {
incr s 1
puts $s
}
}

//for list
proc incrlist list {
set s 0
foreach s $list {
incr s 1
puts $s
}
}

Q4).How to run a package in tcl ?

Ans4:  source <package_name> (or) package require <name>

Q5).How increment a character? For example, I give a and I should get b?

Ans5:L set character “a”
set incremented_char [format %c [expr {[scan $character %c]+1}]] puts “Character before incrementing ‘$character’ : After incrementing ‘$incremented_char'”

>>Read more>>

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HBase Interview Question and Answers

1.What is Apache HBase?

It is a column-oriented database which is used to store the sparse data sets. It is run on the top of Hadoop file distributed system. Apache HBase is a database that runs on a Hadoop cluster. Clients can access HBase data through either a native Java API or through a Thrift or REST gateway, making it accessible by any language. Some of the key properties of HBase include:

• NoSQL: HBase is not a traditional relational database (RDBMS). HBase relaxes the ACID (Atomicity, Consistency, Isolation, Durability) properties of traditional RDBMS systems in order to achieve much greater scalability. Data stored in HBase also does not need to fit into a rigid schema like with an RDBMS, making it ideal for storing unstructured or semi-structured data.
• Wide-Column: HBase stores data in a table-like format with the ability to store billions of rows with millions of columns. Columns can be grouped together in “column families” which allows physical distribution of row values onto different cluster nodes.
• Distributed and Scalable: HBase group rows into “regions” which define how table data is split over multiple nodes in a cluster. If a region gets too large, it is automatically split to share the load across more servers.
• Consistent: HBase is architected to have “strongly-consistent” reads and writes, as opposed to other NoSQL databases that are “eventually consistent”. This means that once a write has been performed, all read requests for that data will return the same value.

Read this blog, to learn more about Apache HBase.

2.Give the name of the key components of HBase

The key components of HBase are Zookeeper, RegionServer, Region, Catalog Tables and HBase Master.

3.What is S3?

S3 stands for simple storage service and it is a one of the file system used by hbase.

4.What is the use of get() method?

get() method is used to read the data from the table.

5.What is the reason of using HBase?

HBase is used because it provides random read and write operations and it can perform a number of operation per second on a large data sets.

>>Read more>>

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Cloud Security Interview Questions and Answers

1) What are the advantages of using cloud computing?
Ans. The advantages of using cloud computing are
a) Data backup and storage of data
b) Powerful server capabilities
c) SaaS ( Software as a service)
d) Information technology sandboxing capabilities
e) Increase in productivity
f) Cost effective & Time saving

2) Mention platforms which are used for large scale cloud computing?
Ans.  The platforms that are used for large scale cloud computing are
a) Apache Hadoop
b) MapReduce
CloudComputing

3) Explain different models for deployment in cloud computing?
Ans. The different deployment models in cloud computing are
a) Private Cloud
b) Public Cloud
c) Community Cloud
d) Hybrid Cloud

4) What is the difference in cloud computing and computing for mobiles?
Ans. Mobile computing uses the same concept as cloud computing. Cloud computing becomes active with the data with the help of internet rather than individual device. It provides users with the data which they have to retrieve on demand. In mobile, the applications runs on the remote server and gives user the access for storage and manage.

5) How user can gain from utility computing?
Ans. Utility computing allows the user to pay only for what they are using. It is a plug-in managed by an organization which decides what type of services has to be deployed from the cloud.
Most organizations prefer hybrid strategy.

6) For a transport in cloud how you can secure your data?
Ans. To secure your data while transporting them from one place to another, check that there is no leak with the encryption key implemented with the data you are sending.

>>Read more>>

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Puppet Interview Questions and Answers

1.What is Puppet ?

Puppet  is a  configuration Tool which is use to automate administration tasks.Puppet Agent(Client) sends request to Puppet Master (Server) and Puppet Master Push Configuration on Agent.

 2.What are Puppet Manifests?
It is a very important question and just make sure you go in a correct flow according to me you should first define Manifests.

Every node (or Puppet Agent) has got its configuration details in Puppet Master, written in the native Puppet language. These details are written in the language which Puppet can understand and are termed as Manifests. Manifests are composed of Puppet code and their filenames use the .pp extension.

Now give an example, you can write a manifest in Puppet Master that creates a file and installs apache on all Puppet Agents (Slaves) connected to the Puppet Master.

3. What is Puppet Module and How it is different from Puppet Manifest?

For this answer I will prefer the below mentioned explanation:
A Puppet Module is a collection of Manifests and data (such as facts, files, and templates), and they have a specific directory structure. Modules are useful for organizing your Puppet code, because they allow you to split your code into multiple Manifests. It is considered best practice to use Modules to organize almost all of your Puppet Manifests.

Puppet programs are called Manifests. Manifests are composed of Puppet code and their file names use the .pp extension.

4. What is Facter in Puppet?

You are expected to answer what exactly Facter does in Puppet so, according to me you should start by explaining:

Facter is basically a library that discovers and reports the per-Agent facts to the Puppet Master such as hardware details, network settings, OS type and version, IP addresses, MAC addresses, SSH keys, and more. These facts are then made available in Puppet Master’s Manifests as variables.

5. What is Puppet Catalog?

I will suggest you to first, tell the uses of Puppet Catalog.

When configuring a node, Puppet Agent uses a document called a catalog, which it downloads from a Puppet Master. The catalog describes the desired state for each resource that should be managed, and may specify dependency information for resources that should be managed in a certain order.

If your interviewer wants to know more about it mention the below points:

Puppet compiles a catalog using three main sources of configuration info:

• Agent-provided data
• External data
• Puppet manifests

>>Read more >>

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Python Pandas Interview Questions and Answers

1Q).What is Pandas/Python Pandas?
Ans1: Pandas is a Python package providing fast, flexible, and expressive data structures designed to make working with “relational” or “labeled” data both easy and intuitive. It aims to be the fundamental high-level building block for doing practical, real world data analysis in Python.

2Q). What is Python pandas used for?
Ans2: pandas is a software library written for the Python programming language for data manipulation and analysis. In particular, it offers data structures and operations for manipulating numerical tables and time series. pandas is free software released under the three-clause BSD license.

 3Q). What is a pandas DataFrame?
Ans3: DataFrame is a 2-dimensional labeled data structure with columns of potentially different types. You can think of it like a spreadsheet or SQL table, or a dict of Series objects. It is generally the most commonly used pandas object.

Q4). What is NP Python?
Ans4: NumPy (pronounced /ˈnʌmpaɪ/ (NUM-py) or sometimes /ˈnʌmpi/ (NUM-pee)) is an extension to the Python programming language, adding support for large, multi-dimensional arrays and matrices, along with a large library of high-level mathematical functions to operate on these arrays.

Q5).What is Matplotlib?
matplotlib is a plotting library for the Python programming language and its numerical mathematics extension NumPy. It provides an object-oriented API for embedding plots into applications using general-purpose GUI toolkits like wxPython, Qt, or GTK+.

Q6).What can I import from NumPy?
Ans6: numpy is the top package name, and doing import numpy doesn’timport submodule numpy.f2py . … The link is established when you do import numpy.f2py. In your above code: import numpy as np # np is an alias pointing tonumpy, but at this point numpy is not linked to numpy.f2py import numpy.

>>Read more>>

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R programming interview questions

1. How R commands are written?

By using # at the starting of the line of code like #division commands are written.

2. What is t-tests() in R?

It is used to determine that the means of two groups are equal or not by using t.test() function.

3.What are the disadvantages of R Programming?

The disadvantages are:-

• Lack of standard GUI
• Not good for big data.
• Does not provide spreadsheet view of data.

4.What is the use of With () and By () function in R?

with() function applies an expression to a dataset.

#with(data,expression)

By() function applies a function t each level of a factors.

#by(data,factorlist,function)

5. In R programming, how missing values are represented?

In R missing values are represented by NA which should be in capital letters.

6. What is the use of subset() and sample() function in R?

Subset() is used to select the variables and observations and sample() function is used to  generate  a random sample of the size n from a dataset.

>>Read more>>

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`mongodb interview questions

1. What makes MongoDB the best?

MongoDB is considered to be best NoSQL database because of :Document-oriented (DO)
High performance (HP)
High availability (HA)
Easy scalability
Rich query language

2. How to do transactions/locking in MongoDB?

MongoDB does not use conventional locking with reduction, as it is planned to be light, high-speed and knowable in its presentation. It can be considered as parallel to the MySQL MyISAM auto entrust sculpt. With simplest business sustain, performance is enhanced, particularly in a structure with numerous servers.

3. When and to what extent does Data get extended to Multi-slice?

The MongoDB scrap stands on a collection. So an album of all substances is kept in a lump or mass. Only when there is an additional time slot, there will be more than a few slice data achievement choices, but when there is more than 1 lump, data gets extended to a lot of slices and it can be extended to 64 MB.

4. Judge against MongoDB with Couchbase and CouchbaseDB?

Although Mongo DB with Couchbase and Couchbase DB are common in many ways, but still they are different in the case of necessities for execution of the model, crossing points, storage, duplications, etc.

5. When do we use Namespace in MongoDB?

During sequencing of the names of the database and collection name Namespace is used.

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Top 25 Perl Interview Questions Prepared by Experts

1.Difference between the variables in which chomp function work ?

Scalar: It is denoted by $ symbol. Variable can be a number or a string.

Array: Denoted by @ symbol prefix. Arrays are indexed by numbers.

The namespace for these types of variables is different. For Example: @add, $add. The scalar variables are in one table of names or namespace and it can hold single specific information at a time and array variables are in another table of names or namespace. Scalar variables can be either a number or a string

2.Create a function that is only available inside the scope where it is defined ?

$pvt = Calculation(5,5);

print(“Result = $pvt\n”);

sub Calculation{

my ($fstVar, $secndVar) = @_;

my $square = sub{

return($_[0] ** 2);

};

return(&$square($fstVar) + &$square($secndVar));

};

Output: Result = 50

3.Which feature of Perl provides code reusability ? Give any example of that feature.

Inheritance feature of Perl provides code reusability. In inheritance, the child class can use the methods and property of parent class

Package Parent;

Sub foo

{

print(“Inside A::foo\n”);

}

package Child;

@ISA = (Parent);

package main;

Child->foo();

Child->bar();

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