#difference between specialization and generalization in dbms

[bcacoursekolkata]

BCA vs. B.Tech: Which Path is Right for You?

Choosing the right educational path is one of the most critical decisions you will make as a student. With various options available, especially in the field of technology, two prominent choices stand out: Bachelor of Computer Applications (BCA) and Bachelor of Technology (B.Tech). Both degrees offer unique advantages and cater to different career aspirations, making the decision challenging for students. This article will explore the key differences, advantages, career opportunities, and factors to consider when deciding between BCA and B.Tech to help you determine which path is right for you.

 Overview of BCA and B.Tech

 What is BCA?        

BCA, or Bachelor of Computer Applications, is a three-year undergraduate program that focuses on computer applications, software development, and information technology. It is designed for students interested in developing practical skills in programming, database management, networking, and web development. BCA emphasizes hands-on learning and projects, equipping students with the knowledge necessary to pursue careers in various IT domains.

 What is B.Tech?

B.Tech, or Bachelor of Technology, is a four-year undergraduate program that provides a comprehensive education in engineering and technology. It is available in various specializations, including Computer Science, Information Technology, Electronics, Mechanical, Civil, and many others. B.Tech programs are structured to offer both theoretical knowledge and practical training in engineering principles, preparing students for complex technological challenges.

 Curriculum and Learning Approach

 BCA Curriculum

The BCA curriculum typically includes subjects such as:

- Programming Languages (C, C++, Java, Python)

- Database Management Systems (DBMS)

- Software Engineering

- Web Technologies

- Networking

- Operating Systems

- Mobile Application Development

The focus is on developing practical skills through projects and real-world applications. BCA programs often encourage students to engage in internships and industry projects to gain hands-on experience, which is crucial for building a strong portfolio.

 B.Tech Curriculum

The B.Tech curriculum is broader and more engineering-focused. It covers subjects such as:

- Mathematics and Physics

- Programming and Data Structures

- Algorithms

- Computer Networks

- Operating Systems

- Digital Logic Design

- Software Engineering

B.Tech students also engage in practical training through laboratory work, projects, and internships. The program is designed to provide a deep understanding of engineering principles and technology, preparing students for advanced roles in the field.

 Key Differences Between BCA and B.Tech

 Duration

- BCA: Typically a three-year program.

- B.Tech: Generally a four-year program.

 Focus and Specialization

- BCA: Concentrates on software applications, programming, and IT management. Ideal for students interested in software development and application programming.

- B.Tech: Covers a broader range of engineering principles, allowing students to specialize in various fields like computer science, electronics, mechanical, and civil engineering.

 Learning Approach

- BCA: More focused on practical skills and applications, often involving projects and hands-on training.

- B.Tech: Combines theoretical knowledge with practical applications, emphasizing engineering concepts and problem-solving.

 Career Pathways

- BCA: Graduates typically pursue roles such as software developer, web developer, systems analyst, or IT support.

- B.Tech: Graduates can work in diverse engineering fields, including software engineering, hardware design, network administration, and research and development.

 Career Opportunities

 Career Paths After BCA

Graduating with a BCA opens various career opportunities, including:

1. Software Developer: Design, develop, and maintain software applications.

2. Web Developer: Create and manage websites, focusing on both front-end and back-end development.

3. Database Administrator: Manage databases, ensuring data integrity and security.

4. Systems Analyst: Analyze and improve IT systems and processes within organizations.

5. Network Administrator: Oversee and maintain computer networks, ensuring seamless connectivity.

6. IT Support Specialist: Provide technical support and troubleshooting for hardware and software issues.

BCA graduates can also pursue higher education, such as MCA (Master of Computer Applications) or MBA (Master of Business Administration), to enhance their career prospects.

 Career Paths After B.Tech

B.Tech graduates enjoy a wider range of career opportunities, including:

1. Software Engineer: Develop and maintain software systems, applications, and tools.

2. Hardware Engineer: Design and develop computer hardware components and systems.

3. Network Engineer: Plan, implement, and manage computer networks and communication systems.

4. Data Scientist: Analyze complex data sets to inform business decisions and strategies.

5. Quality Assurance Engineer: Test software products for quality and performance.

6. Project Manager: Oversee engineering projects, ensuring they are completed on time and within budget.

Additionally, B.Tech graduates can pursue higher studies such as M.Tech (Master of Technology) or MBA for further specialization and career advancement.

 Pros and Cons of BCA and B.Tech

 Pros of BCA

- Shorter Duration: The three-year program allows students to enter the workforce sooner.

- Practical Focus: Emphasis on hands-on training equips students with relevant skills for the industry.

- Specialization in Software: Ideal for students passionate about software applications and development.

 Cons of BCA

- Limited Scope: Career opportunities may be narrower compared to B.Tech, particularly in engineering roles.

- Higher Education Required: Graduates often pursue further studies for better job prospects.

 Pros of B.Tech

- Broader Career Opportunities: Graduates can enter various engineering fields beyond software.

- Higher Salary Potential: B.Tech graduates often command higher starting salaries compared to BCA graduates.

- Robust Curriculum: Comprehensive education in engineering principles prepares students for complex problem-solving.

 Cons of B.Tech

- Longer Duration: The four-year program means students spend more time before entering the workforce.

- Intensive Curriculum: The rigorous academic demands may be challenging for some students.

 Factors to Consider When Choosing Between BCA and B.Tech

 Career Goals

Consider your long-term career aspirations. If you aim to work specifically in software development or IT management, BCA may be a better fit. Conversely, if you are interested in a broader engineering career or wish to specialize in areas like electronics or civil engineering, B.Tech is the more suitable choice.

 Personal Interests

Reflect on your interests and strengths. If you are passionate about coding and software applications, BCA course kolkata may align more closely with your passions. If you enjoy theoretical problem-solving and have an interest in engineering concepts, B.Tech might be the better path.

 Job Market Trends

Research current job market trends in your desired field. B.Tech graduates may have access to a wider array of job opportunities, particularly in engineering and technology. BCA graduates can also find success, especially in software roles, but may face stiffer competition in certain areas.

 Financial Considerations

Evaluate the financial aspects of each program, including tuition fees and potential salary outcomes. While B.Tech programs may be more expensive, they can lead to higher-paying jobs, potentially offsetting the initial costs.

 Further Education

If you plan to pursue higher education, consider how each degree aligns with your future studies. Both BCA and B.Tech graduates can pursue master's degrees, but B.Tech may offer more options for specialization in engineering-related fields.

Choosing between BCA and B.Tech ultimately depends on your career goals, interests, and aspirations. BCA is an excellent choice for those looking to dive into software applications and IT management with a shorter study duration. On the other hand, B.Tech provides a broader engineering education, preparing students for various technical roles with the potential for higher salaries.

It’s essential to assess your strengths, interests, and long-term objectives before making a decision. Consider speaking with academic advisors, industry professionals, or recent graduates to gain further insights into each path. By understanding the nuances of BCA and B.Tech, you can make an informed choice that aligns with your passion and career aspirations, paving the way for a successful future in the ever-evolving world of technology.

[hinditutorialspoint]

DBMS in Hindi - Aggregation

DBMS in Hindi – Aggregation

aggregation in dbms, aggregation kya hai, DBMS Aggregation in Hindi

DBMS Aggregation in Hindi

एकत्रीकरण (aggregation) में, दो entities के बीच संबंध को एक entity के रूप में माना जाता है। एकत्रीकरण में, इसकी संबंधित entities के साथ संबंध एक higher level इकाई में एकत्रित होता है।

उदाहरण के लिए:यदि कोई visitor किसी कोचिंग सेंटर में जाता है, तो वह कभी भी कोर्स के बारे में या सिर्फ सेंटर के बारे में…

[dbhosting]

Which Is The Best PostgreSQL GUI? 2021 Comparison

PostgreSQL graphical user interface (GUI) tools help open source database users to manage, manipulate, and visualize their data. In this post, we discuss the top 6 GUI tools for administering your PostgreSQL hosting deployments. PostgreSQL is the fourth most popular database management system in the world, and heavily used in all sizes of applications from small to large. The traditional method to work with databases is using the command-line interface (CLI) tool, however, this interface presents a number of issues:

It requires a big learning curve to get the best out of the DBMS.

Console display may not be something of your liking, and it only gives very little information at a time.

It is difficult to browse databases and tables, check indexes, and monitor databases through the console.

Many still prefer CLIs over GUIs, but this set is ever so shrinking. I believe anyone who comes into programming after 2010 will tell you GUI tools increase their productivity over a CLI solution.

Why Use a GUI Tool?

Now that we understand the issues users face with the CLI, let’s take a look at the advantages of using a PostgreSQL GUI:

Shortcut keys make it easier to use, and much easier to learn for new users.

Offers great visualization to help you interpret your data.

You can remotely access and navigate another database server.

The window-based interface makes it much easier to manage your PostgreSQL data.

Easier access to files, features, and the operating system.

So, bottom line, GUI tools make PostgreSQL developers’ lives easier.

Top PostgreSQL GUI Tools

Today I will tell you about the 6 best PostgreSQL GUI tools. If you want a quick overview of this article, feel free to check out our infographic at the end of this post. Let’s start with the first and most popular one.

1. pgAdmin

pgAdmin is the de facto GUI tool for PostgreSQL, and the first tool anyone would use for PostgreSQL. It supports all PostgreSQL operations and features while being free and open source. pgAdmin is used by both novice and seasoned DBAs and developers for database administration.

Here are some of the top reasons why PostgreSQL users love pgAdmin:

Create, view and edit on all common PostgreSQL objects.

Offers a graphical query planning tool with color syntax highlighting.

The dashboard lets you monitor server activities such as database locks, connected sessions, and prepared transactions.

Since pgAdmin is a web application, you can deploy it on any server and access it remotely.

pgAdmin UI consists of detachable panels that you can arrange according to your likings.

Provides a procedural language debugger to help you debug your code.

pgAdmin has a portable version which can help you easily move your data between machines.

There are several cons of pgAdmin that users have generally complained about:

The UI is slow and non-intuitive compared to paid GUI tools.

pgAdmin uses too many resources.

pgAdmin can be used on Windows, Linux, and Mac OS. We listed it first as it’s the most used GUI tool for PostgreSQL, and the only native PostgreSQL GUI tool in our list. As it’s dedicated exclusively to PostgreSQL, you can expect it to update with the latest features of each version. pgAdmin can be downloaded from their official website.

pgAdmin Pricing: Free (open source)

2. DBeaver

DBeaver is a major cross-platform GUI tool for PostgreSQL that both developers and database administrators love. DBeaver is not a native GUI tool for PostgreSQL, as it supports all the popular databases like MySQL, MariaDB, Sybase, SQLite, Oracle, SQL Server, DB2, MS Access, Firebird, Teradata, Apache Hive, Phoenix, Presto, and Derby – any database which has a JDBC driver (over 80 databases!).

Here are some of the top DBeaver GUI features for PostgreSQL:

Visual Query builder helps you to construct complex SQL queries without actual knowledge of SQL.

It has one of the best editors – multiple data views are available to support a variety of user needs.

Convenient navigation among data.

In DBeaver, you can generate fake data that looks like real data allowing you to test your systems.

Full-text data search against all chosen tables/views with search results shown as filtered tables/views.

Metadata search among rows in database system tables.

Import and export data with many file formats such as CSV, HTML, XML, JSON, XLS, XLSX.

Provides advanced security for your databases by storing passwords in secured storage protected by a master password.

Automatically generated ER diagrams for a database/schema.

Enterprise Edition provides a special online support system.

One of the cons of DBeaver is it may be slow when dealing with large data sets compared to some expensive GUI tools like Navicat and DataGrip.

You can run DBeaver on Windows, Linux, and macOS, and easily connect DBeaver PostgreSQL with or without SSL. It has a free open-source edition as well an enterprise edition. You can buy the standard license for enterprise edition at $199, or by subscription at $19/month. The free version is good enough for most companies, as many of the DBeaver users will tell you the free edition is better than pgAdmin.

DBeaver Pricing

: Free community, $199 standard license

3. OmniDB

The next PostgreSQL GUI we’re going to review is OmniDB. OmniDB lets you add, edit, and manage data and all other necessary features in a unified workspace. Although OmniDB supports other database systems like MySQL, Oracle, and MariaDB, their primary target is PostgreSQL. This open source tool is mainly sponsored by 2ndQuadrant. OmniDB supports all three major platforms, namely Windows, Linux, and Mac OS X.

There are many reasons why you should use OmniDB for your Postgres developments:

You can easily configure it by adding and removing connections, and leverage encrypted connections when remote connections are necessary.

Smart SQL editor helps you to write SQL codes through autocomplete and syntax highlighting features.

Add-on support available for debugging capabilities to PostgreSQL functions and procedures.

You can monitor the dashboard from customizable charts that show real-time information about your database.

Query plan visualization helps you find bottlenecks in your SQL queries.

It allows access from multiple computers with encrypted personal information.

Developers can add and share new features via plugins.

There are a couple of cons with OmniDB:

OmniDB lacks community support in comparison to pgAdmin and DBeaver. So, you might find it difficult to learn this tool, and could feel a bit alone when you face an issue.

It doesn’t have as many features as paid GUI tools like Navicat and DataGrip.

OmniDB users have favorable opinions about it, and you can download OmniDB for PostgreSQL from here.

OmniDB Pricing: Free (open source)

4. DataGrip

DataGrip is a cross-platform integrated development environment (IDE) that supports multiple database environments. The most important thing to note about DataGrip is that it’s developed by JetBrains, one of the leading brands for developing IDEs. If you have ever used PhpStorm, IntelliJ IDEA, PyCharm, WebStorm, you won’t need an introduction on how good JetBrains IDEs are.

There are many exciting features to like in the DataGrip PostgreSQL GUI:

The context-sensitive and schema-aware auto-complete feature suggests more relevant code completions.

It has a beautiful and customizable UI along with an intelligent query console that keeps track of all your activities so you won’t lose your work. Moreover, you can easily add, remove, edit, and clone data rows with its powerful editor.

There are many ways to navigate schema between tables, views, and procedures.

It can immediately detect bugs in your code and suggest the best options to fix them.

It has an advanced refactoring process – when you rename a variable or an object, it can resolve all references automatically.

DataGrip is not just a GUI tool for PostgreSQL, but a full-featured IDE that has features like version control systems.

There are a few cons in DataGrip:

The obvious issue is that it’s not native to PostgreSQL, so it lacks PostgreSQL-specific features. For example, it is not easy to debug errors as not all are able to be shown.

Not only DataGrip, but most JetBrains IDEs have a big learning curve making it a bit overwhelming for beginner developers.

It consumes a lot of resources, like RAM, from your system.

DataGrip supports a tremendous list of database management systems, including SQL Server, MySQL, Oracle, SQLite, Azure Database, DB2, H2, MariaDB, Cassandra, HyperSQL, Apache Derby, and many more.

DataGrip supports all three major operating systems, Windows, Linux, and Mac OS. One of the downsides is that JetBrains products are comparatively costly. DataGrip has two different prices for organizations and individuals. DataGrip for Organizations will cost you $19.90/month, or $199 for the first year, $159 for the second year, and $119 for the third year onwards. The individual package will cost you $8.90/month, or $89 for the first year. You can test it out during the free 30 day trial period.

DataGrip Pricing

: $8.90/month to $199/year

5. Navicat

Navicat is an easy-to-use graphical tool that targets both beginner and experienced developers. It supports several database systems such as MySQL, PostgreSQL, and MongoDB. One of the special features of Navicat is its collaboration with cloud databases like Amazon Redshift, Amazon RDS, Amazon Aurora, Microsoft Azure, Google Cloud, Tencent Cloud, Alibaba Cloud, and Huawei Cloud.

Important features of Navicat for Postgres include:

It has a very intuitive and fast UI. You can easily create and edit SQL statements with its visual SQL builder, and the powerful code auto-completion saves you a lot of time and helps you avoid mistakes.

Navicat has a powerful data modeling tool for visualizing database structures, making changes, and designing entire schemas from scratch. You can manipulate almost any database object visually through diagrams.

Navicat can run scheduled jobs and notify you via email when the job is done running.

Navicat is capable of synchronizing different data sources and schemas.

Navicat has an add-on feature (Navicat Cloud) that offers project-based team collaboration.

It establishes secure connections through SSH tunneling and SSL ensuring every connection is secure, stable, and reliable.

You can import and export data to diverse formats like Excel, Access, CSV, and more.

Despite all the good features, there are a few cons that you need to consider before buying Navicat:

The license is locked to a single platform. You need to buy different licenses for PostgreSQL and MySQL. Considering its heavy price, this is a bit difficult for a small company or a freelancer.

It has many features that will take some time for a newbie to get going.

You can use Navicat in Windows, Linux, Mac OS, and iOS environments. The quality of Navicat is endorsed by its world-popular clients, including Apple, Oracle, Google, Microsoft, Facebook, Disney, and Adobe. Navicat comes in three editions called enterprise edition, standard edition, and non-commercial edition. Enterprise edition costs you $14.99/month up to $299 for a perpetual license, the standard edition is $9.99/month up to $199 for a perpetual license, and then the non-commercial edition costs $5.99/month up to $119 for its perpetual license. You can get full price details here, and download the Navicat trial version for 14 days from here.

Navicat Pricing

: $5.99/month up to $299/license

6. HeidiSQL

HeidiSQL is a new addition to our best PostgreSQL GUI tools list in 2021. It is a lightweight, free open source GUI that helps you manage tables, logs and users, edit data, views, procedures and scheduled events, and is continuously enhanced by the active group of contributors. HeidiSQL was initially developed for MySQL, and later added support for MS SQL Server, PostgreSQL, SQLite and MariaDB. Invented in 2002 by Ansgar Becker, HeidiSQL aims to be easy to learn and provide the simplest way to connect to a database, fire queries, and see what’s in a database.

Some of the advantages of HeidiSQL for PostgreSQL include:

Connects to multiple servers in one window.

Generates nice SQL-exports, and allows you to export from one server/database directly to another server/database.

Provides a comfortable grid to browse and edit table data, and perform bulk table edits such as move to database, change engine or ollation.

You can write queries with customizable syntax-highlighting and code-completion.

It has an active community helping to support other users and GUI improvements.

Allows you to find specific text in all tables of all databases on a single server, and optimize repair tables in a batch manner.

Provides a dialog for quick grid/data exports to Excel, HTML, JSON, PHP, even LaTeX.

There are a few cons to HeidiSQL:

Does not offer a procedural language debugger to help you debug your code.

Built for Windows, and currently only supports Windows (which is not a con for our Windors readers!)

HeidiSQL does have a lot of bugs, but the author is very attentive and active in addressing issues.

If HeidiSQL is right for you, you can download it here and follow updates on their GitHub page.

HeidiSQL Pricing: Free (open source)

Conclusion

Let’s summarize our top PostgreSQL GUI comparison. Almost everyone starts PostgreSQL with pgAdmin. It has great community support, and there are a lot of resources to help you if you face an issue. Usually, pgAdmin satisfies the needs of many developers to a great extent and thus, most developers do not look for other GUI tools. That’s why pgAdmin remains to be the most popular GUI tool.

If you are looking for an open source solution that has a better UI and visual editor, then DBeaver and OmniDB are great solutions for you. For users looking for a free lightweight GUI that supports multiple database types, HeidiSQL may be right for you. If you are looking for more features than what’s provided by an open source tool, and you’re ready to pay a good price for it, then Navicat and DataGrip are the best GUI products on the market.

Ready for some PostgreSQL automation?

See how you can get your time back with fully managed PostgreSQL hosting. Pricing starts at just $10/month.

While I believe one of these tools should surely support your requirements, there are other popular GUI tools for PostgreSQL that you might like, including Valentina Studio, Adminer, DB visualizer, and SQL workbench. I hope this article will help you decide which GUI tool suits your needs.

Which Is The Best PostgreSQL GUI? 2019 Comparison

Here are the top PostgreSQL GUI tools covered in our previous 2019 post:

pgAdmin

DBeaver

Navicat

DataGrip

OmniDB

Original source: ScaleGrid Blog

[letsmustafa]

COMMUNICATION

I) Introduction :

“Communication is your ticket to success, if you pay attention and learn to do it effectively”  - Theo Gold (Author of Positive Thinking)

The very vital ingredient of life is to share feelings, expressions, to be get heard and add meanings. In fact, the key to life is means to communicate. In other word, we can say, only through communication can human life hold meaning. The process of understanding each other, express ideas, sharing opinion and passing of information or facts. And therefore, it’s imperative to be potent with effective communication skills and techniques in order to enrich the communication process more meaningful and efficient, eventually to be successful in any desired aim or task. We all are bind in relationship whether at home, workplace or in social affairs. Base of successful relationship is communication, and to do it effectively we have to be master in the art of effective communication. To communicate effectively, one must understand the emotion behind the information being said. Understanding communication skills such as; listening, verbal and non-verbal communication, and managing stress can help better the relationships one has with others.

“Your ability to communicate is an important tool in your pursuit of your goals, whether it is with your family, your co-workers or your clients and customers”  - Lee Brown (American politician, criminologist and businessman)

For many, communication seems like a gift. In reality, it is a skill that can be learned through education and practice. Thus, I strongly believe that, each and every individual can grow and become successful in their respective filed and achieve their desired goal if they are championed in effective communication and eager to learn and adopt it as their essential skill set.    

II) About Me :  

Born and brought up in defense area, a town in India, my upbringing has great influenced of military culture. Being retried naval personnel, my father has always given utmost important to disciplined life be it in education, sports or workplace. My mother, a housemaker, truly believe in freedom of open thinking and expression. She has been source of inspiration for us as siblings to pursue our dreams and has her immense support in every manner to achieve it. I, being the youngest, had more privilege to be with her and get nurtured under the shadow as the wife of warrior, a tough warrior in real life. 

As a defense ward, I was fortunate for having had my schooling in military school throughout and chance of meeting and interacting with colleagues coming from different part of the country. Spending my early life with friends, each one with special personality may it be their language, culture, living style, faith etc., was actually the great learning. I must say, defense kids are breed apart. They can adjust everywhere and has ability to manage life with everyone because of their wide exposure in their initial days. They are really blessed with skills to express themselves quite effectively and bond easily to create value network in life.      

Post completing my graduation, I moved to metro city New Delhi. City with full of scope and hope. Opportunity in every field and avenue to fulfill our dreams. I did my post-graduation (PG) here with an ambition of successful career in corporate world, and hence PG in an MBA with finance and marketing as specialization. Since then I’m a working professional in different sectors namely IT/ITES, HR Consulting and Real Estate respectively. My work domain largely involved; business development, marketing communication (MarCom), client relationship (CRM) and event management. My key result area (KRAs) also involved the part of database management (DBMS), management information (MIS) and team handling. 

With having experience of 12 years in different sectors and domain altogether, I always find a scope of learning, improvement and areas to challenge myself to upscale a level ahead from where I was last standing. Upgrading the communication tactics and strategy is organization demand to align with sophisticated corporate purpose and achieving core objectives. Sometime rejection and disapproval are obvious outcome. However, answer to all is keep on brushing and strengthening the communication strategies, keep it effective and nurture leadership quality with dynamic approach simultaneously.

“When you give yourself permission to communicate what matters to you in every situation you will have peace despite rejection or disapproval. Putting a voice to your soul helps you to let go of the negative energy of fear and regret”  - Shannon L. Alder (An inspirational author)

III) Communication strategy and leadership:

Taking role as senior executive level, it’s important to quickly establish or elevate communication skill sets or program. I understand that, the higher we go, more people within the organization would want to know about what we are going to do and how will we do it. We may have inherited hundreds of staff distributed across the world, to whom we may need to communicate regarding our renewed mission, strategy or brand objectives. Furthermore, there may be numerous other stakeholders outside the company that we have to communicate to, like investors, banks, customers etc. Disciplined communication strategy is essential to get across the critical message to key stakeholders without it being drowned by the noise or lost in translation.  

It is crucial to implement excellent communication strategy for success in business world. To encourage members of a company to work together effectively. How team and team members within a company interact determines whether projects will run smoothly or be fraught with challenges. This is where leadership comes in. Good leadership and effective communication go hand in hand. Leaders interact with every team and a large number of employees, how a leader communicates sets the tone for the rest of the organization. Good leader should able to motivate, persuade and encourage others to work towards a common goal.

“When the conduct of men is designed to be influenced, persuasion, kind, unassuming persuasion, should ever be adopted. It is an old and a true maxim, that ‘a drop of honey catches more flies than a gallon of gall” - Abraham Lincoln (Statesman, lawyer and former US president)

It’s essential to identify the leadership style for better understanding on how we must interact with, and perceived by, employees across the organization. Irrespective of the position, we need to develop our individual leadership style and cultivate the essential habit of self-awareness. Even before entering the managerial position, leadership qualities are required depending upon the context and situation. It may be goal oriented, action based, people centric, behavioral etc. Excellent communication skills are required to manage a team at workplace or to manage organization efficiently. And communication gets affected by different leadership styles. To conclude, effective communication and leadership together gives an effective leadership communication. Communication makes a leader effective who develops better understanding in teams. These understanding bring a sense of trust in employees on the leader and on each other, work together, which further reinforce congenial relations with team members and creates an excellent work atmosphere. This enhance the dedication towards work and eventually helps to achieve the desired targets. Conceptual model of effective leadership communication can be explained as below –

Strategic Narrative -

There has been a tangential shift in the way communication is being approached in organizations today. This tangential shift from a formal directive method of communication to a more engaging and inclusive conversational style. The distance between the sender and the receiver is getting shorter and the need for inclusivity and relationship building through communication is getting stronger. One of the major reasons for this shift is the evolution of the workforce and the relationships they hope to make in the workplace. Formality and hierarchy have made way for equality and a flatter organization structure. It’s a common refrain in executive suites these days: “We need a new narrative.” Therefore, story telling is very effective way to excite, attract customers, to engage and motivate. A story that is concise but comprehensive.

“Storytelling can be described as the art of communication using stories and narratives”

When a person needs to be motivated or action is desired out of him/her, communication in the form of stories will generate a stronger reaction when compared to passive data given to him/her.

Active Listening, Receiving and Implementing Feedback –

“When people talk, listen completely. Most people never listen” - Ernest Hemingway (An American journalist, novelist, short-story writer, and sportsman)

Effective leaders know when they need to talk and, more importantly, when they need to listen. employees’ opinions, ideas, and feedback are valuable. And when they do share, actively engage in the conversation—pose questions, invite them to elaborate, and take notes. It’s important to stay in the moment and avoid interrupting. It’s critical, though, that you don’t just listen to the feedback. You also need to act on it, to build up the faith, trust and transparency. By letting your employees know they were heard and then apprising them of any progress you can, or do, make, they’ll feel as though you value their perspective and are serious about improving.

IV) Conclusion :

Communication is the core of effective leadership. To influence and inspire the team, we’ve to be championed in transparency and practicing empathy. Need to understand how other perceive one’s perspective basis on verbal and non-verbal cues. Figure out the scope of improvement and development process and align the plan to guide and track progress.

[vindaloo-softtech]

Laravel vs Yii: Best PHP Framework for Web Development

PHP is a popular general-purpose programming language that is excellent for creating websites and can be incorporated into HTML. 3,090,319 active websites are still utilizing PHP, according to Built with. Other than PHP's fundamental functionality, developers have other options when it comes to building useful web applications. Laravel is a straightforward PHP framework originally developed as a superior alternative to Code igniter, which is often used for developing web-based or web applications. An open-source PHP framework called Yii Framework allows for the quick development of contemporary Web applications. Despite being both extensions of the PHP language, the two frameworks each have unique features that provide them a competitive advantage.

Components of Laravel

Some of the integral components of Laravel Framework are:

●     Artisan, a command-line tool, makes it easier to create models, controls, schedule tasks, and execute a wide range of custom commands.

●     Eloquent is a database interaction framework for Object-Relational Mapping (ORM).

●     Supports all database formats using packages.

●     Allows for versioning and database updates after migrations.

●     Simple PHP code may be used in views thanks to Blade Template Engine.

●     There are hundreds of Laravel standard libraries available.

●     Extensive and practical government material that is constantly updated.

Components of Yii

Some of the key components of the Yii Framework include:

●     DBMS that supports a wide range of DBMS, including PostgreSQL, MySQL, SQLite, Oracle, and others.

●     Support for third-party template engines.

●     Strong community support with several tutorials and official documentation.

●     Gii extension accelerates coding to produce code automatically.

Key Differences between Laravel vs Yii

Although both frameworks are excellent at what they do and essential for web development, there are significant differences between them, including:

Installation

Both frameworks are compatible with PHP 5.4 or newer. Yii has all the required extensions built-in, thus all that is needed to install it is to unpack the package into a web-accessible subdirectory. Laravel, on the other hand, may be installed using Composer or the Laravel installer and needs extra extensions like PHP JSON and MCrypt PHP.

Client-side and scenario-based Validation

While Yii allows users to validate models in both forms, Laravel does not support either sort of validation.

Routing Capabilities

Resource routing is supported by Laravel, but all controllers must specify the routes for each route. Yii's framework by default selects the routes automatically.

CRUD Generation

Only Yii enables automatically producing frequently used interactive code snippets using a specialized plugin called Gii.

Extension Support

Compared to Yii, which only supports a meagre 2800 extensions, Laravel provides a powerful extension support for over 9000 extensions.

Migrations

Both frameworks make migrations relatively simple since they both have methods for ensuring that no data is lost when switching from one database structure to another.

Testing Capabilities

Yii offers PHPUnit and Codeception out of the box, while Laravel offers PHPUnit and various Symfony testing components like Httpkernel, DomCrawler, Browserkit, etc., for detecting and debugging any bugs in operations.

Security

For password security, authentication, defence against SQL Injections, Cross-Site Scripting, and other security risks, Yii and Laravel both provide solutions. While Laravel needs third-party plugins, Yii's role-based access control mechanism is more feature-rich.

Documentation

Yii does not have a high learning curve, however it does not have particularly good documentation. Laravel has a vast, organized documentation with in-depth information but the complexity makes it difficult to find the correct information quickly.

 Wrapping Up

When it comes to audience, Laravel is a fairly narrowly focused framework that solely targets web developers. On the other hand, Yii has a wider clientele and offers support for system administrators, novice web developers, and other users. Vindaloo Softtech can create strong, feature-rich web apps and websites to fulfil the complicated demands of organizations with shorter response times since they have both Yii and Laravel engineers on their staff.

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Most Popular SQL Interview Questions For Basic To Advanced

These SQL Interview Questions are completely dedicated to Modernization of the way we used to maintain records has changed drastically, a lot of data being generated nowadays are in the form of pictures or videos that have become our sole source of keeping memories intact for many years to come. Similarly, multiple organizations and firms have employed a similar method in storing the company data in the form of digitized documents stored away in Database Management Systems (DBMS) which require a special style of language to mine or extract data that the company wishes to extract from its database and here where SQL comes in.

What is SQL?

Structured Query Language (SQL) is a domain-specific programming language that is utilized by skilled professionals to manage data stored in the company’s database. SQL skills are in high demand in the market and serve as the foundational basics for any professional looking for a job or brighter prospects in the data industry. Here are a set of SQL Interview Questions that we believe you should prepare for SQL before going for an interview.

Here are Popular SQL Interview Questions & Answers Lists:-

Q1. Describe a DBMS?

Database Management System (DBMS) is software that is solely responsible for creating, controlling, maintaining, and use of a database. DBMS may be defined as a folder that manages data in a database rather than saving a file in the system.

Q2. Define an RDBMS?

RDBMS abbreviates for Relational Database Management System. It is categorized with the storage of data into a compilation of tables, which are linked by similar topics between the columns of a table. It aids the user with relational operators to influence the data stored in the tables.

Q3. Describe SQL?

SQL abbreviates to Structured Queried Language and aids the operator to communicate with the database. It is a standard operating language that helps execute responsibilities such as recovery, updating, incorporating, and expunging data from the database.

Q4. Define a Database?

It is a structured table of data made to easily access, store, retrieve, and manage data.

Q5. Describe MySQL?

It is a multi-threaded, multiuser structured query language database management system with more than 11 million installations across the globe. The language is the second most well-known and popularly used open-source database programming in use.

MySQL is an oracle-sponsored relational database management system (RDBMS) built on structured query language. It is supported by several operating systems which include Windows, LINUX, iOS, etc.

Q6. My SQL has been written in which language?

C & C++ are the languages in which MySQL has been written

Q7. Mention the technical specifications of MySQL?

Below are the technical specifications of MySQL:-

Drivers

Flexible structure

Geospatial support

Graphical tools

JSON support

OLTP and transactions

High performance

Manageable and easy to use

MySQL Enterprise Monitor

MySQL Enterprise Security

Replication and high availability

Security & storage management

Q8. Describe the difference between SQL and MySQL?

SQL stands for structured query language and is used to interact with databases like MySQL

MySQL is a database management system used for the structured storage of data

A PHP script is needed to store and mine data from this database

SQL is a computer language whereas MySQL is an application

SQL is used for the creation of various Database Management Systems (DBMS)

Q9. Distinguish between the database and a table?

There are 4 noticeable differences between a database & a table:-

Tables showcase structured data in a database, whereas a database is a collection of tables

Tables are grouped with relations to create a dataset; the dataset forms the database.

Data stored in the table in any form is part of the database, but the other way around is not possible.

A table is a collection of rows and columns used to store data, whereas a database is a collection of organized data and features used to access tables.

Q10. Distinguish between Tables and fields?

A table is a compilation of cells that are structured in a model which eventually form tables and rows. Columns may be categorized as a vertical collection of cells and rows may be categorized as a horizontal collection of cells.

There is also a reference to the cells laid out in a column to create an entity also termed a field once a header is provided to the so-called column.

A field may have several rows which may constitute a record.

E.g.

Table name:- Employee

Field name’s:- Emp ID, Emp Name, Date of Birth

Data:- 2866, Daniel Decker, 29/02/1984

Q11. What is the purpose of using a MySQL database server?

Below are some of the reasons why MySQL server is so famous with its users:-

MySQL is an open-source database management system that is free of charge for private developers and small enterprises.

MySQL’s community is vast and supportive, thus any issues faced are resolved at the earliest.

Has multiple stable versions available

It extremely quick, dependable and is beginner-friendly

The download is free of cost

Q12. Describe the various tables present in MySQL?

There are majorly 5 tables present in MySQL: –

MyISAM

Heap

Merge

INNO DB

ISAM

Q13. How can an Operator install MySQL?

There are multiple ways of installing MySQL in one’s system, but the best way to do it is manual. The manual installation allows the user to gain a better understanding of the system and aids in an additional grasp of the database. There are several benefits linked to the manual installation of MySQL:-

Reinstalling, creating backups, or moving databases can be achieved in less than a minute.

Provides precise control over how and when MySQL closes or starts.

MySQL can even be installed in a USB drive

Q14. How can a user check the MySQL version?

In WINDOWS MySQL command-line tool shows the version information without using any flags, but for a piece of more detailed information the operator may always feed in the below-mentioned command

MySQL> SHOW VARIABLES LIKE “%version%”.

and it will show a detailed discretion of the version of SQL that the user is using.

Q15. How to add columns in MySQL?

Several cells in a table are what may constitute a column and a set of cells in a column constitutes a row. To add columns in MySQL, the following statement of ALTER TABLE may be used:

ALTER TABLE table_name

ADD COLUMN column_name column_definition [FIRST|AFTER existing_column].

Q16. In MySQL how can you delete a table?

The drop table statement not only removes the data in the table, but it also removes the structure and definition from the database permanently. Thus, the user needs to be extremely careful whilst using this command, the reason is that once deleted there is no recovery option in MySQL. The command is as follows:-

DROP TABLE table_name

Q17. Define a Primary Key?

A primary Key may be described as a compilation of fields that meticulously define a row. This is a Unique Key and has an unspoken NOT NULL constraint, implicating Primary keys cannot have NULL values.

Q18. Define a Unique Key?

This key provides a separately pre-defined constraint that exclusively distinguishes every record in the database which insinuates a distinctiveness for the column or the set of columns.

Q19. Define a Foreign Key?

This is a key that can be linked to the Primary Key of another table. Connections need to be fabricated between the two tables by providing a reference to the foreign key with the primary key of another table.

Q20. Describe a Join?

It is a keyword utilized to question data from multiple tables established on the connections between the fields of the table. Keys play a crucial part when JOINs are employed.

Q21. Describe the multiple ‘JOIN’ and explain each?

JOIN’s are tools that help the user retrieve data and depend on the links between tables. Following are the types of ‘JOIN’ used in SQL:-

Inner JOIN – This JOIN is used to return rows with at least a single match of rows between tables

Right, JOIN – This JOIN helps return rows that are similar between tables and all rows of the right-hand side table. To simplify this JOIN returns all rows from the right-hand side table irrespective of any matches from the left-hand side table.

Left JOIN – This JOIN helps return rows that are similar between tables and all rows of the left-hand side table. To simplify this JOIN returns all rows from the left-hand side table irrespective of any matches from the right-hand side table.

Full JOIN – This JOIN returns rows if there are any similar rows in any of the tables. So basically, this JOIN returns all the rows from both the right-hand and left-hand side tables.

Q22. Define Normalization?

It is the procedure of reducing redundancies and dependencies by structuring fields and tables of a database. The primary motive of ‘Normalization’ is to add, modify, and delete that can be merged into a single table.

Q23. Define De-Normalization?

It is a method employed to gain access to data from higher to lower normal types of databases. It is also a way of implementing redundancy into a table by integrating data from the correlated tables.

Q24. Distinguish the multiple normalizations?

Normalizations may be dissected into 5 forms:-

First Normal Form (1NF) :- It helps in eliminating all identical columns from a table which aids the formation of tables for the associated data and recognition of distinctive columns.

Second Normal Form (2NF):– Meeting all the obligations of the 1NF. Retaining the subsets of data in separate tables and the creation of relations between tables using primary keys.

Third Normal Form (3NF):– This shall meet all the constraints of 2NF and eradicate the columns which are not reliant on the primary key limits.

Fourth Normal Form (4NF):– Meeting all the obligations of the 3NF and it shall not have multi-valued dependencies.

Q25. Define a View?

The view is a computer-generated table that comprises a subsection of data enclosed in a table. Views are NOT virtually present and require a lesser amount of storage capacity. The view can have data of one or more tables pooled in one and depends on the connection.

Q26. Define an Index?

An index is a routine tweaking method to permit faster reclamation of records from a table. An Index designs an entry for every value which makes data recovery quicker.

Q27. Describe the distinct kinds of Indexes?

There are primarily 3 types of Index’s:-

Unique Index – This style of Indexing does not grant the field to have identical values if the column is uniquely indexed. This Index can be used spontaneously once the primary key is defined.

Clustered Index – This style of index rearranges the raw order of the table and searches based on key values. Each table may consist of only one Clustered Index.

Non-Clustered Index – Non-Clustered Index does not modify the raw order of the table and retains the plausible order of data. Each table may consist of 999 non-clustered indexes.

Q28. Define a Cursor?

A database cursor is a command which facilitates a cross-over of the rows/records in a table. This may be visible as a hint to one row in a collection of rows. It is extremely useful for traversing the retrieval, addition, and removal of database archives.

Q29. Define a Database relationship and what are they in SQL?

It is defined as the link between the tables in a database. There are several database-based relationships, and they are as follows:-

One to One relationship

To Many relationships

Many to One relationship

Self-referencing relationship

Q30. Describe a Query?

A database query is a code created to recover information from the database. The query may be fabricated in a way to match the user’s expectation of the result set which may simply be a question to the database.

Q31. Describe a Subquery?

As the word describes, it is a query inside a query. The exterior query is known as the – Main Query and the innermost query is called a Subquery. Subqueries are forever implemented first and the outcome from the Subquery is then passed on to the main query.

Q32. Describe the types of Subqueries?

There are majorly 2 styles of subqueries:-

Correlated Subquery – These cannot be considered as independent queries but may refer to the column in a table listed in the FROM the list of the main query.

Non-Correlated Subquery – These may be considered as independent queries and the output of these subqueries may be substituted in the main query.

Q33. Define a Stored Procedure?

This procedure is a function that comprises several SQL statements to access the DBMS. Multiple SQL statements are compiled into a ‘Stored Procedure’ and may be employed anywhere as per requirement basis.

Q34. Define a ‘Trigger’?

The trigger is a code that automatically executes with some event on a table or with a view in a database. E.g., On the joining of a new hire, new records need to be entered in fields like employee ID, Name, Date of birth, etc.

Q35. Distinguish between DELETE and TRUNCATE commands?

DELETE command is utilized to delete rows from the table and a WHERE clause may be applied for a provisional set of considerations. Commit and Rollback may be executed post deletion of the statement.

TRUNCATE deletes every row from the table. Truncate control cannot be turned backward.

Q36. Define Local and global variables and describe their disparities?

Local variables are the variables that can be applied or occur within the function. They are unknown to the other functions and cannot be referred to or utilized. Variables can be established whenever the functions are called.

Global variables are the variables that can be employed or be present all over the program. An identical variable proclaimed in a global variable cannot be utilized in functions. Global variables cannot be established whenever a particular function is called.

Q37. Define a CONSTRAINT?

A constraint may be employed to restrict the data type of a table. It may also be specified at the time of creating or altering the table. Some examples of constraints are:-

NOT NULL

CHECK

DEFAULT

UNIQUE

PRIMARY KEY

FOREIGN KEY

Q38. Define Data Integrity?

It defines the precision and consistency of the data stored in a database. It may also identify integrity constraints to implement business guidelines on the data when it is registered into the application or database.

Q39. Describe auto Increment?

This enables the operator to fabricate a new number to be generated when a record is inserted into the table. AUTOINCREMENT keyword may be used in Oracle and IDENTITY keyword may be used in an SQL SERVER.

This keyword is used when the primary key is used.

Q40.Distinguish between Cluster and Non-Cluster Index?

Cluster Index is employed for the convenient recovery of data from the database by adjusting the way the records are stored. A database sorts out rows by columns which are destined to be Clustered Index.

A non-Clustered Index does not adjust the way data was stored in the database, rather fabricates a completely different entity inside the table. It usually points back to the original table rows after investigating.

Q41. Describe a Datawarehouse?

It is a fundamental storehouse of data from numerous data sources. Data are collected, transformed, and made available for mining and online processing. Warehouse data have a subcategory of data dubbed as Data Mart.

Q42. Define a Self-Join?

It is a query employed to evaluate itself. It is utilized to assess values in a column with other values in the same column and table.

Q43. Define a Cross-Join?

Cross join describes as a query to calculate the results of the number of rows in the first table multiplied by several rows in the second table. If a WHERE clause is applied in a cross join, then the query will act like an INNER JOIN.

Q44. Describe User Defined functions and their types?

User-defined functions are fabricated to create logic whenever required. It is not required to write the same logic multiple times. Rather, the function may be called or deployed at any given point in time.

There are 3 styles of User-defined functions:-

Scalar Functions – returns unit, return clause defined by variant

Inline table-valued functions, return table as a return

Multi-statement valued functions returns table as a return

Q45. Describe Collation?

It describes as a compilation of guidelines that establish how character data may be categorized and compared. It can be used to assess A and other language characters, also depending on the width of the characters.

all values may be used to compare these character data.

Q46. Describe the distinct styles of Collation sensitivity?

These are the different types of collation sensitivities:-

Case Sensitivity – A & a, and B & b.

Accent Sensitivity

Kana Sensitivity – Japanese Kana characters.

Width Sensitivity – Single-byte & double-byte character.

Q47. Define recursive Stored Procedure?

A stored procedure that demands by itself until it achieves some kind of boundary condition. This recursive function or procedure helps computer operators use the identical set of codes ‘n’ number of times.

Q48. How can a user add foreign keys in MySQL?

This is the key to linking one or more tables together in MySQL. It helps in matching the primary key field of another table to connect the two tables. It allows the user to have a parent-child relationship within the tables. This can be executed either way:-

Using the CREATE TABLE command

Using the ALTER TABLE command

Following is the syntax used to define a foreign key using CREATE or ALTER TABLE

[CONSTRAINT constraint_name]

FOREIGN KEY [foreign_key_name] (col_name, …)

           REFERENCES parent_tbl_name (col_name, …)

Q49. Describe how can the user create a database in MySQL workbench?

To do so the initial step would be to:-

launch the MySQL workbench and log in using a username and password

Choose the Schema menu from the navigation tab

Right-click under the schema menu and pick the ‘Create Schema’ option.

Or

Click on the database icon ( similar to a barrel)

A new dialog box would appear

After filling in all the details in the dialog box

Click on Apply and Finish to complete the database creation.

Q50. How can the user create a Table in MySQL workbench?

Launch the MySQL workbench

Go to the navigation tab

Choose the ‘Schema Menu’ which will showcase all the previously created databases

Select any database and right-click on it

In the sub-menus, we need to select the tables option

Right-click on the tables sub-menu

Choose ‘Create table Option’

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Top 50 Sql Meeting Questions And Responses

https://bit.ly/3tmWIsh enables the individual to develop a unique number to be produced whenever a new document is inserted in the table. AUTOMOBILE INCREMENT is the keyword for Oracle, AUTO_INCREMENT in MySQL and IDENTIFICATION keyword phrase can be used in SQL WEB SERVER for auto-incrementing. Mainly this keyword phrase is used to develop the main key for the table. Normalization sets up the existing tables and its areas within the data source, leading to minimum replication. It is utilized to simplify a table as long as feasible while retaining the one-of-a-kind fields. If you have really little to state on your own, the job interviewer power believe you have void to claim. pl sql interview concerns I make myself really feel magnificent in front the meeting begins. With this inquiry, the recruiter will certainly judge you on exactly how you prioritise your job listing. I expect functions with damien once more in the future stressful. You mightiness need a compounding of different sorts of inquiries in order to to the full cover the concern, as well as this may diverge betwixt individuals. Prospects show up to meetings with a finish of impressing you. A primary trick is a unique kind of unique secret. A foreign secret is made use of to preserve the referential web link honesty in between 2 data tables. linked here prevents actions that can destroy web links in between a youngster as well as a moms and dad table. A primary secret is used to specify a column that distinctively determines each row. Void value and replicate values are not permitted to be entered in the main essential column. However, you could not be provided this tip, so it gets on you to remember that in such a situation a subquery is precisely what you require. After you go through the essential SQL meeting inquiries, you are most likely to be asked something more certain. And also there's no far better feeling on the planet than acing a inquiry you practiced. Yet if all you do is technique SQL interview concerns while ignoring the basics, something is mosting likely to be missing out on. Request way too many concerns might jump the meeting and reach them, however demand none will make you look unenthusiastic or not really prepared. When you are taking the examination, you should prioritise making sure that all parts of it run. Leading 50 google analytics interview concerns & solutions. Nerve-coaching from the meeting men that will blast your restless feelings so that you can be laser-focused and surefooted when you land in the spot. Terrific, trying, and im type of gallant i was capable to fix it under such stress.

Those that pass the phone or photo meeting move on to the in-person meetings. Again, it's crafty inquiry, and also not simply in damage of operations it out. On the far side permitting myself to get some howling meemies out, i genuinely delighted in the chance to get a far better feel for campus/atmosphere. Understanding the extremely certain response to some very specific SQL meeting concerns is terrific, yet it's not mosting likely to aid you if you're asked something unanticipated. Do not get me wrong-- targeted prep work can absolutely help. Note that this not a Not Void constraint and do not perplex the default worth restraint with forbiding the Void entrances. The default worth for the column is established just when the row is created for the first time and column worth is disregarded on the Insert. Denormalization is a database optimization technique for raising a data source infrastructure performance by including repetitive data to one or more tables. Normalization is a data source design method to organize tables to minimize data redundancy and also information reliance. SQL restraints are the set of rules to limit the insertion, deletion, or updating of information in the databases. They restrict the type of information entering a table for preserving information accuracy and also integrity. CREATE-- Used to produce the data source or its objects like table, index, feature, sights, activates, and so on. A special trick is made use of to uniquely determine each record in a database. A CHECK constraint is used to restrict the values or kind of information that can be kept in a column. A Main key is column whose values uniquely determine every row in a table. The major role of a main type in a data table is to preserve the internal integrity of a information table. Query/Statement-- They're frequently utilized reciprocally, yet there's a mild difference. Listed below are different SQL interview questions as well as answers that declares your knowledge concerning SQL and supply brand-new understandings and also discovering the language. Experience these SQL meeting inquiries to refresh your expertise before any type of interview. Therefore, your following job will not have to do with discussing what SQL restraints as well as secrets suggest as a whole, although you need to be very knowledgeable about the concept. You will certainly instead be provided the opportunity to show your capacity to clarify on a specific type of an SQL restriction-- the foreign vital restriction. Write a SQL question to locate the 10th tallest optimal ("Elevation") from a "Mountain" table. Adjustment to the column with NULL value or perhaps the Insert procedure defining the Null worth for the column is enabled. Click on the Establish Key Trick toolbar switch to set the StudId column as the primary key column. A RIGHT OUTER JOIN is one of the SIGN UP WITH procedures that allows you to specify a JOIN provision. It preserves the unparalleled rows from the Table2 table, joining them with a NULL in the form of the Table1 table. And then, as presently as we cut that prospect, everybody burst out laughing however you can't be in on the technique." there are several " weak points" that you can develop into favorable scenarios to share an response that your interviewer will certainly respect as well as see. - this environs covers the hardware, servers, operating system, internet internet browsers, various other software program system, etc. Obligations that you were not able-bodied to be complete. "i find out which project is near substantial, and afterwards i try to do that task initially earlier finish the doing well one. Permanently instance, there are technique of accountancy plan, arsenal bundle, and so on. While https://geekinterview.net to ask generic inquiries, you take the chance of not acquiring the discerning info you need to make the very best hiring decision. Question optimization is a procedure in which database system compares various query strategies and also pick the inquiry with the least expense. https://tinyurl.com/c7k3vf9t produced on more than one column is called composite main trick. ERASE removes some or all rows from a table based upon the condition. TRIM removes ALL rows from a table by de-allocating the memory pages. The operation can not be rolled back DECREASE command eliminates a table from the data source completely. The major distinction in between the two is that DBMS conserves your information as files whereas RDMS saves your information in tabular type. Additionally, as the keyword Relational indicates, RDMS allows different tables to have connections with each other making use of Main Keys, Foreign Keys and so on. This creates a dynamic chain of power structure between tables which likewise uses useful constraint on the tables. Think that there go to the very least 10 records in the Hill table. That's why leading companies are progressively relocating far from generic questions and are instead providing prospects a split at real-life inner situations. "At Airbnb, we offered prospective hires access to the tools we utilize as well as a vetted data set, one where we understood its restrictions as well as troubles. It permitted them to focus on the form of the information and frame solution to problems that were purposeful to us," keeps in mind Geggatt. A Check restraint look for a details condition prior to putting data into a table. If the data passes all the Inspect restraints then the data will certainly be inserted into the table or else the information for insertion will certainly be thrown out. The CHECK constraint makes certain that all worths in a column satisfy specific problems. A Not Void constraint restricts the insertion of null worths into a column. If we are making use of a Not Void Restraint for a column after that we can not ignore the worth of this column throughout insertion of information into the table. The default constraint allows you to establish a default worth for the column.

[firsttimeinterview]

Leading 50 Sql Interview Questions As Well As Responses

Auto increment enables the individual to create a unique number to be created whenever a brand-new record is put in the table. CAR INCREMENT is the keyword for Oracle, AUTO_INCREMENT in MySQL and IDENTITY key phrase can be made use of in SQL WEB SERVER for auto-incrementing. Mainly this keyword phrase is used to create the primary key for the table. Normalization sets up the existing tables and its fields within the database, resulting in minimal replication. It is utilized to streamline a table as long as feasible while keeping the special fields. If you have really little to claim on your own, the recruiter power believe you have null to state. pl sql interview inquiries I make myself feel magnificent in front the interview begins. With this question, the employer will certainly evaluate you on just how you prioritise your job listing. I expect operations with damien once again in the future strained. You mightiness require a compounding of different kinds of questions in order to fully cover the concern, and also this may diverge betwixt individuals. Candidates appear to interviews with a surface of thrilling you. A primary key is a unique sort of unique trick. A international key is utilized to keep the referential web link stability between 2 information tables. It protects against actions that can ruin links between a kid and a moms and dad table. A primary secret is utilized to define a column that uniquely determines each row. Null value and duplicate values are not permitted to be entered in the main crucial column. However, you may not be given this hint, so it is on you to remember that in such a scenario a subquery is exactly what you require. After you experience the basic SQL meeting inquiries, you are likely to be asked something extra certain. And also there's no better feeling worldwide than acing a concern you practiced. But if geekinterview do is method SQL interview inquiries while neglecting the basics, something is mosting likely to be missing out on. Request too many inquiries might jump the meeting as well as reach them, but request none will make you look unenthusiastic or not really prepared. When you are taking the test, you should prioritise making certain that all parts of it run. Leading 50 google analytics interview questions & answers. Nerve-coaching from the interview people that will certainly blast your troubled sensations to ensure that you can be laser-focused as well as surefooted as soon as you land in the hot seat. Terrific, attempting, and also im type of gallant i was capable to settle it under such tension. Those who pass the phone or picture meeting go on to the in-person meetings. Once again, it's crafty concern, and not simply in damages of operations it out. On the far side permitting myself to get some shouting meemies out, i really taken pleasure in the possibility to obtain a better feel for campus/atmosphere. Knowing the extremely certain answers to some really particular SQL meeting questions is excellent, however it's not going to help you if you're asked something unexpected. Don't get me wrong-- targeted prep work can absolutely help. Keep in https://is.gd/snW9y3 that this not a Not Null restraint as well as do not puzzle the default worth constraint with forbiding the Null entries. The default worth for the column is set just when the row is created for the first time and column worth is ignored on the Insert. Denormalization is a data source optimization strategy for enhancing a database infrastructure performance by including redundant data to one or more tables. Normalization is a database design strategy to organize tables to lower information redundancy and data reliance. SQL constraints are the set of regulations to restrict the insertion, deletion, or upgrading of information in the databases. They restrict the kind of data going in a table for keeping information precision and integrity. PRODUCE-- Used to develop the data source or its items like table, index, feature, views, sets off, etc. A special key is used to distinctly identify each document in a database. A CHECK restraint is utilized to limit the worths or kind of data that can be stored in a column. A Primary key is column whose worths distinctively determine every row in a table. The main role of a main key in a data table is to maintain the internal stability of a information table. Query/Statement-- They're frequently utilized reciprocally, yet there's a slight difference. Listed here are various SQL interview concerns as well as solutions that declares your understanding regarding SQL as well as provide new understandings as well as discovering the language. Experience these SQL interview inquiries to rejuvenate your understanding before any type of meeting.

As a result, your following task won't be about describing what SQL restrictions and tricks imply generally, although you need to be really accustomed to the principle. You will rather be given the chance to show your capacity to specify on a details type of an SQL restriction-- the foreign crucial constraint. Write a SQL query to find the 10th tallest peak (" Altitude") from a " Hill" table. Adjustment to the column with VOID worth and even the Insert procedure specifying the Void value for the column is permitted. Click the Set Primary Trick toolbar button to set the StudId column as the primary crucial column. A RIGHT OUTER SIGN UP WITH is one of the JOIN procedures that enables you to specify a SIGN UP WITH clause. It maintains the unrivaled rows from the Table2 table, joining them with a NULL in the shape of the Table1 table. And afterwards, as currently as we cut that possibility, everyone burst out laughing yet you can not be in on the technique." there are many " weak points" that you can become favorable situations to reveal an response that your recruiter will certainly value and see. - this environs covers the ironware, servers, running plan, internet internet browsers, various other software program system, etc. Duties that you were not able-bodied to be full. "i figure out which task is near considerable, and afterwards i try to do that project initially previously end up the being successful one. Permanently example, there are approach of audit package, arsenal package, etc. While it's much easier to ask common questions, you take the chance of not obtaining the discerning details you need to make the best hiring decision. Question optimization is a procedure in which database system compares various question techniques and pick the question with the least cost. Main key developed on more than one column is called composite main trick. REMOVE removes some or all rows from a table based on the problem. ABBREVIATE gets rid of ALL rows from a table by de-allocating the memory pages. The procedure can not be rolled back DECLINE command eliminates a table from the data source completely. The main distinction in between the two is that DBMS conserves your information as documents whereas RDMS saves your information in tabular type. Also, as the keyword Relational implies, RDMS permits various tables to have connections with one another using Primary Keys, Foreign Keys etc. This creates a dynamic chain of hierarchy in between tables which also uses practical constraint on the tables. Think that there go to the very least 10 records in the Mountain table. That's why leading firms are progressively relocating far from common concerns and also are instead supplying candidates a split at real-life inner circumstances. "At Airbnb, we provided possible hires access to the tools we make use of and also a vetted information collection, one where we knew its restrictions and troubles. It allowed them to concentrate on the shape of the data as well as framework answers to problems that were significant to us," notes Geggatt. A Check constraint look for a certain condition prior to inserting data right into a table. If the data passes all the Inspect restrictions then the data will certainly be inserted right into the table or else the data for insertion will be disposed of. The CHECK constraint guarantees that all values in a column satisfy particular conditions. https://tinyurl.com/c7k3vf9t restricts the insertion of null worths right into a column. If we are using a Not Void Constraint for a column after that we can not neglect the worth of this column during insertion of data right into the table. The default constraint enables you to establish a default value for the column.

[hinditutorialspoint]

DBMS in Hindi - Specialization

DBMS in Hindi – Specialization

specialization in dbms, specialization kya hai, dbms specialization in hindi

DBMS Specialization in Hindi

specialization एक top-down दृष्टिकोण है, और यह generalization के विपरीत है। specialization में, एक higher level की इकाई को दो lower level की entities में तोड़ा जा सकता है।

specialization का उपयोग एक इकाई set के subset की पहचान करने के लिए किया जाता है जो कुछ विशिष्ठ विशेषताओ को साझा करता है।

[trendingjobs]

Leading 50 Sql Interview Questions And Also Solutions

Automobile increment enables the individual to create a serial number to be produced whenever a new document is placed in the table. AUTOMOBILE INCREMENT is the keyword for Oracle, AUTO_INCREMENT in MySQL and IDENTITY keyword phrase can be utilized in SQL WEB SERVER for auto-incrementing. Mainly this search phrase is used to produce the main trick for the table. Normalization organizes the existing tables and its areas within the data source, causing minimal duplication. It is utilized to simplify a table as high as possible while preserving the special areas. If you have actually little to state for yourself, the job interviewer power believe you have void to claim. pl sql meeting questions I make myself feel divine ahead the interview starts. With sql queries interview questions , the employer will certainly judge you on exactly how you prioritise your task checklist. I look forward to functions with damien once again in the future strained. You mightiness require a compounding of dissimilar types of questions in order to fully cover the concern, and this may split betwixt participants. https://bit.ly/3tmWIsh turn up to interviews with a surface of impressing you. A main secret is a unique sort of unique trick. A foreign secret is used to maintain the referential web link stability in between two information tables. It prevents activities that can damage web links in between a kid and also a moms and dad table. A main secret is utilized to specify a column that distinctively identifies each row. Null worth as well as replicate worths are not permitted to be entered in the main key column. However, you might not be provided this tip, so it gets on you to bear in mind that in such a circumstance a subquery is exactly what you require. After you go through the basic SQL meeting concerns, you are most likely to be asked something more details. As well as there's no far better feeling on the planet than acing a inquiry you exercised. Yet if all you do is method SQL meeting concerns while disregarding the essentials, something is going to be missing. Demand a lot of questions may leap the interview and also reach them, but request none will certainly make you look unenthusiastic or unprepared. When you are taking the test, you need to prioritise making certain that all parts of it run. Top 50 google analytics meeting inquiries & responses. Nerve-coaching from the meeting guys that will blast your restless sensations to make sure that you can be laser-focused as well as surefooted once you land in the spot. Terrific, attempting, and im sort of gallant i was qualified to resolve it under such stress. Those who pass the phone or photo interview proceed to the in-person meetings. Once again, it's smart question, and not just in damages of workings it out. Beyond permitting https://geekinterview.net to get some screaming meemies out, i truly appreciated the chance to obtain a far better feel for campus/atmosphere. Recognizing the very details solution to some very details SQL interview questions is excellent, but it's not going to aid you if you're asked something unforeseen. Don't get me wrong-- targeted prep work can certainly help. Keep in mind that this not a Not Null restriction and do not puzzle the default value restriction with disallowing the Void access. The default value for the column is established just when the row is produced for the first time and also column worth is neglected on the Insert. Denormalization is a data source optimization technique for boosting a data source facilities performance by including redundant information to one or more tables. Normalization is a database design strategy to arrange tables to decrease information redundancy and information dependence. SQL constraints are the set of rules to limit the insertion, removal, or updating of data in the data sources. They restrict the kind of information entering a table for keeping data precision and also honesty. PRODUCE-- Used to develop the database or its objects like table, index, feature, views, activates, and so on. A distinct key is made use of to uniquely determine each document in a database. A CHECK constraint is used to restrict the values or type of data that can be kept in a column. A Primary key is column whose values distinctively recognize every row in a table. The main function of a main type in a information table is to maintain the interior honesty of a information table. Query/Statement-- They're typically used mutually, yet there's a minor difference. Listed here are various SQL meeting inquiries as well as answers that reaffirms your understanding about SQL as well as offer brand-new insights as well as learning more about the language. Undergo these SQL meeting questions to freshen your expertise prior to any type of meeting. Consequently, your next task will not be about discussing what SQL restraints and keys indicate generally, although you have to be really accustomed to the idea. You will certainly instead be offered the chance to demonstrate your capability to clarify on a particular type of an SQL restraint-- the international essential restraint. Compose a SQL query to find the 10th tallest peak (" Altitude") from a "Mountain" table. Alteration to the column with VOID value or perhaps the Insert procedure defining the Null value for the column is enabled. Click on the Set Main Key toolbar button to establish the StudId column as the main essential column. A RIGHT OUTER SIGN UP WITH is among the JOIN procedures that permits you to define a SIGN UP WITH condition. It maintains the unequaled rows from the Table2 table, joining them with a NULL in the shape of the Table1 table.

And after that, as presently as we reduced that prospect, every person broken out laughing however you can not be in on the method." there are many "weaknesses" that you can turn into favorable scenarios to reveal an solution that your interviewer will certainly respect and also see. - this environments covers the ironware, servers, operating system, web internet browsers, various other software application system, etc. Tasks that you were not able-bodied to be total. "i find out which job is near considerable, and after that i try to do that job first previously end up the doing well one. For good example, there are technique of audit plan, arsenal bundle, and so on. While it's much easier to ask generic questions, you run the risk of not acquiring the careful details you need to make the most effective hiring determination. Query optimization is a process in which database system compares various query methods and select the query with the least cost. Primary vital created on more than one column is called composite primary trick. REMOVE removes some or all rows from a table based on the problem. TRUNCATE eliminates ALL rows from a table by de-allocating the memory pages. The procedure can not be curtailed DROP command removes a table from the database totally. The primary difference in between the two is that DBMS saves your info as files whereas RDMS saves your details in tabular form. Also, as the keyword Relational implies, RDMS allows various tables to have relationships with one another making use of Main Keys, Foreign Keys and so on. This develops a dynamic chain of power structure between tables which likewise uses helpful constraint on the tables. Assume that there are at the very least 10 documents in the Hill table. That's why leading firms are increasingly relocating far from generic concerns and also are rather providing prospects a crack at real-life internal circumstances. "At Airbnb, we provided potential hires access to the devices we make use of as well as a vetted data set, one where we understood its restrictions as well as issues. It allowed them to concentrate on the shape of the information as well as framework answers to problems that were meaningful to us," notes Geggatt. A Examine constraint checks for a certain condition prior to putting information into a table. If the data passes all the Examine restraints then the data will be inserted right into the table or else the data for insertion will certainly be thrown out. The CHECK restriction guarantees that all worths in a column please specific conditions. A Not Null restraint restricts the insertion of null worths into a column. If we are making use of a Not Void Restriction for a column then we can not neglect the value of this column throughout insertion of data into the table. The default constraint enables you to establish a default worth for the column.

[joeyrob1]

Intro Primer For WEKA Machine Learning Software

Contents

1 Intro Primer For WEKA Machine Learning Software

2 Why Weka?

2.0.1 Data Preprocessing

2.0.2 Classification

2.0.3 Clustering

2.0.4 Attribute Selection

2.0.5 Data Visualization

2.0.6 Time Series Forecasting

3 Intro to the Weka GUI

3.0.1 1. Download and Install

3.0.2 2. Weka Explorer

3.0.3 3. Weka Experimenter

3.0.4 4. Knowledge Flow

4 References

5 Conclusion

Intro Primer For WEKA Machine Learning Software

(3 votes, average: 5.00 out of 5)

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Weka is a machine learning software and data mining workbench. It’s an acronym for the Waikato Environment for Knowledge Analysis. It contains a collection of visualization tools and algorithms for data analysis and predictive modeling. It is a very convenient tool with wonderful graphical user interfaces for you to experiment with machine learning and data mining models on your data.

Hoang Pham Truc Phuong, hptphuong@gmail.com, is the author of this article and he contributes to RobustTechHouse Blog for our Machine Learning column. RobustTechHouse is a web & mobile app development house focusing on Financial (Fintech) and ECommerce sectors and likes to dabble with data analysis and machine learning too.

[Updated on 25 May 2015] Also see our follow up post on Intro Primer To WEKA Explorer For Machine Learning

Why Weka?

Weka supports several standard data mining tasks with many standard data mining algorithms ranging from normal ones to really complex ones. All of Weka’s techniques are predicated on the assumption that the data is available as a single flat file or relation, where each data point is described by a fixed number of attributes. Here are some main features of Weka:

Data Preprocessing

Weka supports various file formats e.g, CSV, Matlab etc and its own file format (ARFF). It also supports most common database management systems (DBMS) including HSQL, SQL SERVER, MySQL, PostgreSQL etc through java connections. For data processing, Weka has over 75 methods for filtering, ranging from basic to advanced operators eg principal component analysis.

Classification

Weka has a lot of classification methods. Classifiers can be divided into “Bayesian” methods (Naive Bayes, Bayesian nets etc.), lazy methods (nearest neighbor and variants), rule-based methods (decision tables, OneR, RIPPER), tree learners (C4.5, Naive Bayes trees, M5, J.48 etc), function-based learners (linear regression, SVMs, Multilayer Perceptron, Gaussian processes) and miscellaneous methods.

Clustering

Weka has most classic algorithms for clustering such as: Simple KMeans, Hierarchical class clustering, simple expectation maximization (EM).

Attribute Selection

The set of attributes used is essential for classification performance. Various selection criteria and search methods are available.

Data Visualization

Data can be inspected visually by plotting attribute values against the class, or against other attribute values. Classifier output can be compared to training data in order to detect outliers and observe classifier characteristics and decision boundaries. For specific methods, there are specialized tools for visualization, such as a tree viewer for any method that produces classification trees, a Bayes network viewer with automatic layout, and a dendrogram viewer for hierarchical clustering

Time Series Forecasting

This is a new function in Weka from version 3.7.x (version for Developers). Weka supports many methods for predicting time series as function-based learning (Gaussian processing, linear regression, Multilayer perceptron neural network, SMOreg-support vector machine for regression), lazy method (K-nearest neighbours, Locally weighted learning and KStar) and trees (Random forest, random tree)

From my experience, here are some reasons which make Weka a good toolbox for Machine Learning: 1. Easy to use graphical user interfaces. 2. Contains most of the powerful algorithms published for machine learning. 3. Free availability under the GNU General Public License. 4. Portability, since it is fully implemented in the Java programming language and runs on almost any modern computing platform. 5. A comprehensive collection of data pre-processing and modelling techniques.

Intro to the Weka GUI

1. Download and Install

Download from Weka Download Link. There are two versions of Weka: Stable version (3.6.12) and developer version (3.7.12). I personally prefer the developer version because it allows me to install more packages, e.g, time series forecasting.

After downloading, unzip the zip file and run this command: > java -Xmx1000M -jar weka.jar

Weka version 3.6 (Stable Version)

Weka Version 3.7 (Developer Version)

The above shows the subtle differences between the standard and developer versions.

To connect to a DBMS, you should to do the following steps:

1. Download java connection compatible with your DBMS,e.g, mysql-connector-java, sql-connector-java 2. Use this syntax to run weka with DBMS:

> java -Xmx1000M -cp weka path:java_connection_path weka.gui.GUIChooser.

Here is the example I used to connect to mysql: > java -Xmx1000M -cp /home/phuong/weka-3-7-12/weka.jar:/home/phuong/java_conn/mysql-connector-java-5.1.34-bin.jar weka.gui.GUIChooser

2. Weka Explorer

In, Weka explorer, you can visualize, clean your data and try some algorithms for clustering, classification and forecasting. Some features are different between the stable version & developer version of Weka. Here, I am using “Weka Explorer” in the developer version.

Weka Explorer

The explorer interface is divided into 11 different tabs in two tab lines (top line contain 5 features and the other have 6 features) . The top line is only have in the developer version.

RConsole: It is an extension which combines Weka with R language and reuses some a lot of the awesome functions from R.

RConsole

Parallel Coordinates Plot: a common way of visualizing high-dimensional geometry and analyzing multivariate data.

Parallel Coordinates Plot

Projection Plot: To apply algorithms such as clustering algorithms and visualize the results on the graph directly.

Visualize 3D: Plot your data in 3D space!

Visualize 3D

Forecasting: This function is used for time series forecasting. You will find some famous algorithms such as SVM, regression in here.

Forecast: Graph

Forecast: Output & Evaluation

Preprocess: Load a dataset and manipulate the data into a form that you want to work with.

Preprocess

Classify: Select and run classication and regression algorithms to operate on your data.

Cluster: Select and run clustering algorithms on your dataset.

Associate: Run association algorithms to extract insights from your data.

Select Attributes: Run attribute selection algorithms on your data to select those attributes that are relevant to the feature you want to predict.

Visualize: Visualize the relationship between attributes.

3. Weka Experimenter

Unlike Weka Explorer that is used for analysis and experimenting with algorithms, “Weka Experimenter” is for designing experiments with your selection of algorithms and datasets, running experiments and analyzing the results. For example, the user can create an experiment that runs several schemes against a series of datasets and then analyse the results to determine if one of the schemes is statistically better than the other schemes.

Weka Experimenter

4. Knowledge Flow

Knowledge Flow helps you create a process to apply machine learning. It helps you graphically design your process and run the design that you created. The analysis process goes like this: loading and transforming of input data, followed by running of algorithms and then presentation of results.

Weka Knowledge Flow Environment

References

You can review some links below for more information about Weka.

An Introduction To The WEKA Data Mining System

Data Mining With Weka

More Data Mining With Weka

WEKA Documentations

Conclusion

Here we provided an Intro Primer For WEKA Machine Learning Software. Hope you found it useful.

If you like our articles, please follow and like our Facebook page where we regularly share interesting posts  and check out our other blog articles.

RobustTechHouse is a leading tech company focusing on mobile app development, ECommerce, Mobile-Commerce and Financial Technology (FinTech) in Singapore. If you are interested to engage RobustTechHouse on your projects, you can contact us here.

Intro Primer For WEKA Machine Learning Software was originally published on RobustTechHouse - Mobile App Development Singapore

[mokosmart]

LoRa frequency range

LoRa uses the CSS (Chirp Spread Spectrum) modulation which uses a frequency spreading method as a modulation technique. So-called chirp pulses are sent as symbols, which increase or decrease in LoRa frequency continuously over time. The data transmission is then realized by the sequential sequence of these chirp pulses.

Special properties

Since LoRa works in the ISM frequency bands (433 MHz, 868 MHz and 915 MHz), the radiated transmission power is limited. In order to have a larger radio range than conventional modulation types such as To achieve FSK (Frequency Shift Keying), the receiver sensitivity has been significantly improved with LoRa. The LoRa receiver can still successfully receive and decode a useful LoRa signal up to 20 dB below the noise level, which results in a receiver sensitivity of a maximum of -149 dBm. Compared to the maximum FSK sensitivity of approx. –125 dBm to -130 dBm, LoRa offers a significant improvement. With the FSK receiver, the signal can only be successfully decoded if the useful signal is approx.

Thanks to the property that LoRa can still successfully receive a useful signal up to 20 dB below the noise level, the robustness to radio interference is significantly better than that of FSK. FSK systems only work correctly if the interference signal is at least 10 dB weaker than the useful signal. In the best case, LoRa systems can still receive the useful signal if the interference signal is 20 dB stronger than the useful signal.

Limitations

From the graphic above you can see that LoRa can receive about 30 dB weaker signals than with FSK. However, there are two restrictions that somewhat relativize this big difference.

• First, the LoRa modulation is broadband than the FSK modulation, which means that the noise level of the LoRa receiver is generally higher than that of the FSK receiver. Specifically, doubling the bandwidth increases the noise level by 3 dB. • Secondly, LoRa can only receive a useful signal up to 20 dB below the noise level at very slow data rates of ≤ 0.5 kbit / s. As soon as the data rate is increased, either the negative signal-to-noise ratio increases further towards zero or the bandwidth has to be increased further, which in turn increases the noise level.

Comparison measurement between LoRa and FSK

To find out how good LoRa really is, a direct comparison between LoRa and FSK should be carried out. For this purpose, our previously used standard FSK transceivers (CC1020 and CC1101) are compared with the data from the LoRa / FSK transceiver SX1261.

TransceiverModulation

Max sensitivity according to the datasheet

Data rateRX- bandwidth

CC1020FSK-118 dBm2.4 kBit/s12.5 kHz

CC1101FSK-116 dBm0.6 kBit/s58 kHz

SX1261FSK-125 dBm0.6 kBit/s4 kHz

SX1261LoRa-149.2 dBm0.02 kBit/s8 kHz

According to the information from the datasheets, LoRa achieves at least a 24dB better maximum sensitivity than with the best FSK transceiver (SX1261). Compared to the old FSK transceivers (CC1020 and CC1101), the maximum sensitivity is even 31 or 33 dB better. Since it can be assumed that the radio range can be doubled for every 10 dB more sensitivity, a 4 to 8 times the radio range should be possible with LoRa compared to FSK.

However, it is also noticeable that the maximum LoRa sensitivity is achieved with an extremely slow data rate of only 0.02 kbit / s. In order to obtain a direct, meaningful comparison between the different transceivers, the sensitivity of all transceivers is determined at the same data rate. According to Semtech's manufacturer, LoRa would have to achieve about 7 to 10 dB more sensitivity at the same data rate as FSK.

The SX1261 transceiver with LoRa modulation achieves 4 - 6 dB more sensitivity than with FSK modulation. In comparison to the CC1020 8 - 11 dB and in comparison to the CC1101 13 - 17 dB more sensitivity is achieved. It is striking that the lower the data rate is chosen, the more sensitivity gain can be achieved with LoRa.

Another view shows the energy-saving potential of LoRa. In order to achieve the same sensitivity as with FSK, approximately 4 times the data rate can be used with LoRa. The same radio telegram thus becomes 4 times shorter and the energy consumption also drops by a factor of 4.

Conclusion:

As with all radio transceivers, the maximum LoRa sensitivity of -149 dBm is only achieved at the lowest data rate. This data rate for LoRa is only approx. 0.02 kbit / s and is therefore unusable for many applications. However, if such low data rates can be used, 4 times the radio range is theoretically possible compared to modern FSK transceivers.

If the LoRa data rate is increased to 1.2 kBit / s to 10 kBit / s, LoRa achieves approx. 4-6 dB more sensitivity compared to modern FSK transceivers. Compared to older FSK transceivers such as the CC1101 or CC1020, the radio range can even be doubled or tripled with LoRa.

There is an interesting energy-saving option in applications where the current FSK sensitivity was sufficient. If the same sensitivity is to be achieved with LoRa, the data rate can be increased by a factor of 4 compared to FSK, whereby the energy consumption can also be reduced by a factor of 4.

For us, LoRa technology represents an interesting alternative for applications with data rates up to 10 kbit / s, since the radio range can be increased massively compared to the older transceivers. Of particular interest to us is the possibility of connecting to the LoRaWAN network, as this means that IoT applications can be connected to the Internet practically anywhere.

With our LoRa module "TRX433-70" we are ready for future innovative LoRa projects.

Radio transmission with LoRa

The meter readings, switching commands and other information can be transmitted from the concentrator module to the router and back in a variety of ways. If the wired transmission is not possible or too expensive, radio transmission with LoRa can be an alternative for remote reading.

The LoRa radio standard

LoRa stands for Long Range, i.e. high (radio) range and is an alternative radio standard to the known technologies such as UMTS or LTE. In many countries, LoRa has already established itself as the basis for a communication standard in the so-called Internet of Things (IoT), for machine-to-machine (M2M) communication and for industry and smart city applications.

The LoRa radio standard, like other radio technologies, uses the free LoRa frequency bands from the license-free ISM bands (Industrial, Scientific and Medical). In Europe, these are the bands in the 433 and 868 MHz range. By using a special radio procedure, the so-called frequency spread, the technology is almost immune to interference. The range between transmitter and receiver is between 2 and 15 km, depending on the environment and built-up area. Due to the high sensitivity of -137 dBm, high penetration of buildings can be achieved. The radio signals penetrate deep into the interior of buildings and basements. Especially at campsites where the metallic covers of the caravans and mobile homes often weaken the signal strength of WLAN, radio transmission with LoRa is superior here. The data rate at LoRa is between 0.3 and 50 kbit / s.

Applications for LoRa

LoRa is mainly used in applications in which very little data is to be transmitted over a long distance in a very energy-saving manner. These data are usually measured values, status signals or manipulated values.

Differences between WLAN, LoRa and mobile radio

WLAN and mobile radio are designed to transmit large amounts of data. Relatively short ranges are accepted. LoRa, on the other hand, is optimized for the transmission of small amounts of data over large distances. The following table shows some differences between the different radio standards.

LoRaWAN (long range wide area network)

Low Power WANs (LPWANs) are network concepts for the Internet of Things (IoT) and machine-to-machine communication (M2M). LPWANs are characterized by the fact that they can cover distances of up to 50 km and require very little energy. There are several technical approaches to realizing the LPWANs. One from ETSI: ETSI GS LTN, other names are LoRaWAN, Weightless and RPMA, which stands for Random Phase Multiple Access.

So that the bridgeable distance is not impaired too much by the free space attenuation, some of the LPWAN concepts mentioned use frequencies in ISM bands at 433 MHz and 868 MHz. Few also work in the ISM band at 2.4 GHz.

For example, as regards SigFox as LoRaWAN (Long Range Wide Area Network), it uses the ISM band at 868 MHz (USA 915 MHz) in Europe. The bridgeable distance range is over 5 km in the urban area and over 15 km outside the city. There are also radio transceivers in the LoRa frequency range of 2.4 GHz with which a range of 10 km can be bridged. LoRa transmission is a combination of Chirp Spread Spectrum (CSS) and Software Defined Radio (SDR). A key advantage is that signals that are up to 20 dB below the noise level can still be detected. The LoRaWAN concept supports bidirectional communication, mobility and location-based services.

The end devices are connected to a base station, which in turn receives the information encrypted from a backbone via TCP / IP and the SSL protocol. To ensure that the battery life of the end components is as long as possible, all data rates and the RF output signals are managed by the LoRaWAN network and the end components are controlled via an adaptive data rate (ADR). There are three-terminal device classes: Class A devices can communicate bidirectionally and have a planned transmission window in the uplink, class B devices also have a planned transmission window in the downlink and the transmission window for class C devices is continuously open. The LoRaWAN technology is standardized by the LoRa Alliance.

LoRaWan - Framework for wireless networks

LoRaWan is a specification and describes a framework for wireless networks. It is used in networks with little data traffic, for example in sensor networks. LoRaWan (LongRangeWideAreaNetwork) is a so-called LPWAN (Low Power Wide Area Network) protocol. This article shows the frequencies used by LoRaWan and the available classes of end devices.

LoRa frequency varies in different regions of the world. However, it is necessary here to get more information before starting up a LoRa device in order to set the correct frequency. The following table shows the correct frequencies for each country or continent:

LoRaWan is also treated like a star topology. Gateways forward messages from the end devices to a specific access server. The gateways are connected via the standard server via standard internet connections.

Bidirectional devices There are three main bidirectional classes handled by End:

Class A

The uplink data always originate from the end device. The uplink message is followed by 2 short reception windows for downlink messages. These downlink messages can also be included for confirmation messages as well as for device parameters. Since the communication between the terminal and the gateway will only ever be from the terminal, there may be a waiting time between the detailed new device parameters and the implementation of the terminal.

Between the actual transmission time contacts, Class A devices can put their LoRa module completely in an energy-saving mode. This will change energy efficiency.

Class B

Class B, others to class A's fault windows, become further reception windows. Class B devices are synchronized via cyclically sent beacons. These beacons are used to communicate, and other reception windows are open at other times. The loss is that the latency can be determined in advance, the loss of energy consumption as a component number. However, the energy consumption remains low enough for battery-operated applications.

Class C

Class C significantly reduces the latency for the downlink, since the receiving window of the end device is always heard as long as the device itself does not give any messages. For this reason, the trusted server can start a downlink transmission. A time change between class A and C is particularly important in battery-powered legal contracts, for example, "firmware-over-the-air" updates.

This article is from https://www.mokosmart.com/lora-frequency/

Follow and know us more on https://www.mokosmart.com/ if you’re interested in developing LoRa products!

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Producing single photons from a stream of single electrons

SAW-driven lateral n-i-p junction, and its electrical and optical properties. a Schematic of the device. Electron and hole surface gates induce electrons (n-region) and holes (p-region) in a GaAs quantum well, forming a lateral n-i-p junction along an etched 1D channel. A SAW is generated by applying an RF signal to a transducer (placed 1 mm from the n-i-p junction). b Schematic diagram showing the band structure of the n-i-p junction modulated by the SAW potential, for an applied forward bias less than the bandgap. A single electron is carried in each SAW minimum, creating a single photon when it recombines with a hole. c S-D current (top) and EL intensity (bottom) as a function of applied RF frequency at an RF power of 9 dBm. They both show a significant enhancement around 1.163 GHz, which is the resonant SAW frequency of the IDT. d SAW-driven EL intensity as a function of time. The 860 ps periodic feature corresponds to the applied SAW frequency of 1.163 GHz. e Energy spectrum of the SAW-driven EL. The spectrum shows a peak at 1.531 eV (FWHM ~ 1 meV), which matches the exciton energy in the quantum well. Credit: Nature Communications (2020). DOI: 10.1038/s41467-020-14560-1

Researchers at the University of Cambridge have developed a novel technique for generating single photons, by moving single electrons in a specially designed light-emitting diode (LED). This technique, reported in the journal Nature Communications, could help the development of the emerging fields of quantum communication and quantum computation.

A single photon, the elementary particle of light, can carry a quantum bit of information over hundreds of kilometres. Therefore, a source that can generate single photons is an important building block in many quantum technologies. Up to now, single-photon sources have been made in research labs from self-assembled quantum dots in semiconductors, or structural defects in diamonds. The formation of these dots and defects is a random process, so it is hard to predict the location and the photon energy (or wavelength) of these single-photon sources. This randomness may pose a challenge in integrating a source into a large quantum network.

In this article, the researchers show that they can generate a single photon in a different, controlled, way, without the need for a quantum dot or a defect, by moving only one electron at a time to recombine with a ‘hole’ (a missing electron in a filled ‘band’ of electrons).

‘Imagine trying to send a digital message by firing a stream of blue or red balls over a wall in the following way. A conveyor belt with ball-sized indentations drags a series of white balls up a slope and drops the balls off a cliff at the end. Each ball picks up speed as it falls, is then sprayed blue or red (depending on the message) as it bounces off to the side and over the wall’, explains Dr. Tzu-Kan Hsiao, who did the experiment during his Ph.D. at Cambridge.

`The indentations in the conveyor belt can only carry one ball each.

Only one ball gets sprayed at a time, and there’s no chance some of the balls are intercepted by an eavesdropper without the person on the receiving end noticing a missing ball, whereas if sometimes two or more balls come at a time, the eavesdropper can catch odd balls and the receiver is none the wiser. In that way, some of the message may be unintentionally disclosed.’

‘In the experiment, we made a device near the surface of Gallium Arsenide (GaAs) by using only industry-compatible fabrication processes. This device consists of a region of electrons close to a region of holes, and a narrow channel in between’, says Professor Christopher Ford, team leader of the research.

‘In order to transport only one electron at a time, we launch a sound wave along the surface. In GaAs such a “surface acoustic wave” also creates an accompanying electrical potential wave, in which each potential minimum carries just one electron. The potential wave, like a conveyor belt, brings individual electrons to the region of holes one after another. A series of single photons is generated when each electron quickly recombines with a hole before the next electron arrives.

Each single photon could be given one of two polarisations to carry a message such that an eavesdropper cannot intercept the message without being detected.

In addition to being a novel single-photon source, more importantly, it may be possible with this new technique to convert the state of an electron spin to the polarisation state of a photon. By bridging semiconductor-based quantum-computers using single photons as ‘flying’ qubits, the ambitious goal of building large-scale distributed quantum-computing networks may be achieved.

A cavity leads to a strong interaction between light and matter

More information: Tzu-Kan Hsiao et al, Single-photon emission from single-electron transport in a SAW-driven lateral light-emitting diode, Nature Communications (2020). DOI: 10.1038/s41467-020-14560-1

Provided by University of Cambridge

Citation: Producing single photons from a stream of single electrons (2020, February 14) retrieved 17 February 2020 from https://phys.org/news/2020-02-photons-stream-electrons.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

New post published on: https://www.livescience.tech/2020/02/17/producing-single-photons-from-a-stream-of-single-electrons/

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300+ TOP Business Intelligence Interview Questions and Answers

Business Intelligence Interview Questions for freshers experienced :-

1. What is Business Intelligence? Business Intelligence is a process for increasing the competitive advantage of a business by intelligent use of available data in decision making. The five key stages of Business Intelligence: Data Sourcing Data Analysis Situation Awareness Risk Assessment Decision Support 2. What is a Universe in Business Intelligence? A "universe" is a "Business object" terminology. Business objects also happens to be the name of the company. The universe is the interfacing layer between the client and the datawarehouse . The universe defines the relationship among the various tables in the datawarehouse. Or Universe is a semantic layer between the database and the user interface (reports). 3. What is OLAP in Business Intelligence? Online Analytical Processing, a category of software tools that provides analysis of data stored in a database. OLAP tools enable users to analyze different dimensions of multidimensional data. For example, it provides time series and trend analysis views. The chief component of OLAP is the OLAP server, which sits between a client and a database management systems (DBMS). The OLAP server understands how data is organized in the database and has special functions analyzing the data. A good OLAP interface has writes an efficient sql and reads an accurate data from db.To design and architect having good knowledge on DB understanding the report requirements. 4. What are the various modules in Business Objects product? Business Objects Reporter Reporting & Analyzing tool Designer Universe creation database interaction connectivity Supervisor - For Administrative purposes Webintelligence - Access of report data through internet BroadCast Agent - For scheduling the reports Data Integrator - The ETL tool of Business Objects, designed to handle huge amounts of data 5. What is OLAP, MOLAP, ROLAP, DOLAP, HOLAP? Explain with Examples? OLAP - On-Line Analytical Processing. Designates a category of applications and technologies that allow the collection, storage, manipulation and reproduction of multidimensional data, with the goal of analysis. MOLAP - Multidimensional OLAP. This term designates a cartesian data structure more specifically. In effect, MOLAP contrasts with ROLAP. Inb the former, joins between tables are already suitable, which enhances performances. In the latter, joins are computed during the request. Targeted at groups of users because it's a shared environment. Data is stored in an exclusive server-based format. It performs more complex analysis of data. DOLAP - Desktop OLAP. Small OLAP products for local multidimensional analysis Desktop OLAP. There can be a mini multidimensional database (using Personal Express), or extraction of a datacube (using Business Objects). Designed for low-end, single, departmental user. Data is stored in cubes on the desktop. It's like having your own spreadsheet. Since the data is local, end users dont have to worry about performance hits against the server. ROLAP - Relational OLAP. Designates one or several star schemas stored in relational databases. This technology permits multidimensional analysis with data stored in relational databases. Used for large departments or groups because it supports large amounts of data and users. HOLAP:Hybridization of OLAP, which can include any of the above. 6. Why an infocube has maximum of 16 dimensions? It depends upon the Database limits provided to define the Foreign key constraint, e.g. in Sql Server 2005, the recommended max limit for foreign keys is 253, but you can define more. 7. What is BAS? What is the function? The Business Application Support (BAS) functional area at SLAC provides administrative computing services to the Business Services Division and Human Resources Department. We are responsible for software development and maintenance of the PeopleSoft? Applications and consultation to customers with their computer-related tasks. 8. Name some of the standard Business Intelligence tools in the Market? Some of the standard Business Intelligence tools in the market According to their performance MICROSTRATEGY BUSINESS OBJECTS,CRYSTAL REPORTS COGNOS REPORT NET MS-OLAP SERVICES Or Seagate Crystal report SAS Business objects Microstrategy Cognos Microsoft OLAP Hyperion Microsoft integrated services 9. How do we enhance the functionality of the reports in BO? You can format the BO Reports by using various features available. You can turn the table reports into a 2-Dimensional or 3-Dimensional charts. You can apply an Alert to show some data in a different format , based on some business rule. You can also create some prompts, which will asks user to give some input values before seeing the reports, this way they will see only filtered data. There are many similar exciting options available to enhance the reports. 10. What are dashboards? A management reporting tool to gauge how well the organization company is performing. It normally uses "traffic-lights" or "smiley faces" to determine the status.

Business Intelligence Interview Questions 11. Explain about Auditing in BO XI R2? What is the use of it? Auditor is used by the business objects administrators to know the complete information of the business intelligence system. it monitors entire BIsystem at a glance. Analyzes usage and change impact optimises the BI deployment 12. How do we Tune the BO Reports for Performance Improvement? We can tune the report by using index awareness in universe 13. Why we ca not create an aggregate on an ODS Object? Operational Data Store has very low data latency. Data moved to ODS mostly on event based rather than time based ETL to Data Warehouse/Data Mart. ODS is more closer to OLTP system. We don't normally prefer to store aggregated data in OLTP. So it is with ODS. Unlike data warehouse where data is HISTORICAL, ODS is near real time(NRT). So data aggregation is less important is ODS as data keeps changing. 14. What is hierarchy relationship in a dimension. whether it is: 1:1 1:m m:m 1:M 15. How to connect GDE to Co Operating system in Abinitio? We can connect Ab Initio GDE with Co>operating system using Run->Settings.In there u can specify the host IP address and the connection type .Refer Ab Initio help for further details. 16. Explain the Name of some standard Business Intelligence tools in the market? Some of the standard Business Intelligence tools in the market According to there performance MICROSTRATEGY BUSINESS OBJECTS,CRYSTAL REPORTS COGNOS REPORT NET MS-OLAP SERVICES 17. What are the various modules in Business Objects product Suite? Supervisor: Supervisor is the control center for the administration and security of your entire BusinessObjects deployment. Designer: Designer is the tool used to create, manage and distribute universe for BusinessObjects and WebIntelligence Users. A universe is a file that containe connection parameters for one or more database middleware and SQL structure called objects that map to actual SQL structure in the database as columns,tables and database. BusinessObjects Full client Reporting tool: Helps to create businessobjects reports based on the universe and also from the other data sources. BusinessObjects Thin client Reporting tool: Helps to querry and analysis on the universe and also share the report among other users. It doesnt require any software, just need a webbrowser and the system connected to the businessobjetcs server. Auditor: Tool is used for monitor and analysis user and system activity. Application Foundation: This module covers a set of products which is used for Enterprise Performance Management (EPM). The tools are Dashboard manager Scorecard Performance Management Applications 18. From where you Get the Logical Query of your Request? The logical SQL generated by the server can be viewed in BI Answers. If I have not understood the question, Please raise your voice. 19. Major Challenges You Faced While Creating the RPD? Every now and then there are problems with the database connections but the problem while creating the repository RPD files comes with complex schemas made on OLTP systems consisting of lot of joins and checking the results. Th type of join made need to be checked. By default it is inner join but sometimes the requirement demands other types of joins. There are lot of problems with the date formats also. 20. What are Global Filter and how thery differ From Column Filter? Column filter- simply a filter applied on a column which we can use to restrict our column values while pulling the data or in charts to see the related content. Global filter- Not sure. I understand this filter will have impact on across the application but I really dont understand where and how it can be user. I heard of global variables but not global filters. 21. How to make the Delivery Profilers Work? When we are Use SA System how Does SA Server understand that It needs to use it For Getting the User Profile information? 22. Where to Configure the Scheduler? We configure the OBIEE schedular in database. 23. How to hide Certain Columns From a User? Application access level security- Do not add the column in the report, Do not add the column in the presentation layer. 24. How can we Enable Drills in a Given Column Data? To enable Drill down for a column, it should be included in the hirarchy in OBIEE. Hyperion IR has a drill anywhere feature where dont have to define and can drill to any available column. 25. Is Drill Down Possible without the attribute being a Part of a Hierarchical Dimension? No 26. How do u Conditional Format.? while creating a chat in BI Answers, you can define the conditions and can apply colour formatting. 27. What is Guided Navigation? I think it is just the arrangement of hyperlinks to guide the user to navigate between the reports to do the analysis. 28. How is Webcat File Deployed Across Environment? How the users Created Differs From RPD/Answers/Dashboards Level? RPD users can do administrator tasks like adding new data source, create hirarchies, change column names where as Answers users may create new charts, edit those charts and Dashboard users may only view and analyse the dashboard or can edit dashboard by adding/removing charts objects. 29. Online/Offline Mode how it Impact in Dev and Delpoyment? Online Mode- You can make changes in the RPD file and push in changes which will be immediately visible to the users who are already connected. This feature we may use in production environment. Offline mode- can be useful in test or development environment. 30. Explain the concepts and capabilities of Business Intelligence. Business Intelligence helps to manage data by applying different skills, technologies, security and quality risks. This also helps in achieving a better understanding of data.Business intelligence can be considered as the collective information. It helps in making predictions of business operations using gathered data in a warehouse. Business intelligence application helps to tackle sales, financial, production etc business data. It helps in a better decision making and can be also considered as a decision support system. 31. Name some of the standard Business Intelligence tools in the market. Business intelligence tools are to report, analyze and present data. Few of the tools available in the market are: Eclipse BIRT Project:- Based on eclipse. Mainly used for web applications and it is open source. Freereporting.com:- It is a free web based reporting tool. JasperSoft:- BI tool used for reporting, ETL etc. Pentaho:- Has data mining, dashboard and workflow capabilities. Openl:- A web application used for OLAP reporting. 32. Explain the Dashboard in the business intelligence. A dashboard in business intellgence allows huge data and reports to be read in a single graphical interface. They help in making faster decisions by replying on measurable data seen at a glance. They can also be used to get into details of this data to analyze the root cause of any business performance. It represents the business data and business state at a high level. Dashboards can also be used for cost control. Example of need of a dashboard: Banks run thousands of ATM’s. They need to know how much cash is deposited, how much is left etc. 33. Explain the SQL Server 2005 Business Intelligence components. SQL Server Integration Services:- Used for data transformation and creation. Used in data acquisition form a source system. SQL Server Analysis Services: Allows data discovery using data mining. Using business logic it supports data enhancement. SQL Server Reporting Services:- Used for Data presentation and distribution access. Business Intelligence Questions and Answers Pdf Download Read the full article

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Top 50 Sql Interview Questions As Well As Responses

Auto increment allows the user to create a serial number to be generated whenever a new document is placed in the table. VEHICLE INCREMENT is the key phrase for Oracle, AUTO_INCREMENT in MySQL as well as IDENTIFICATION keyword can be made use of in SQL WEB SERVER for auto-incrementing. Primarily this search phrase is made use of to develop the main key for the table. Normalization sets up the existing tables and also its areas within the database, leading to minimal replication. It is used to simplify a table as much as possible while keeping the one-of-a-kind areas. If you have truly little to claim for yourself, the interviewer power think you have null to say. pl sql meeting concerns I make myself feel divine ahead the meeting begins. With this concern, the recruiter will evaluate you on exactly how you prioritise your job checklist. I expect functions with damien once again in the future tense. You mightiness need a compounding of different types of inquiries in order to to the full cover the problem, and also this may split betwixt participants. Prospects turn up to interviews with a surface of thrilling you. A main trick is a special sort of one-of-a-kind trick. A foreign secret is made use of to keep the referential web link integrity between 2 data tables. It protects against actions that can damage web links in between a kid and also a parent table. A primary key is made use of to specify a column that distinctively identifies each row. Null worth and also replicate values are not allowed to be entered in the primary essential column. Nonetheless, you might not be offered this tip, so it gets on you to remember that in such a scenario a subquery is specifically what you require. After you undergo the fundamental SQL meeting inquiries, you are most likely to be asked something more certain. As well as there's no far better sensation in the world than acing a inquiry you exercised. Yet if all you do is practice SQL interview questions while neglecting the essentials, something is going to be missing. Demand too many questions might leap the meeting as well as get to them, however demand none will certainly make you look unenthusiastic or unprepared. When you are taking the test, you ought to prioritise making sure that all parts of it run. Leading 50 google analytics interview concerns & responses. Nerve-coaching from the meeting men that will certainly blast your agitated sensations to make sure that you can be laser-focused and also surefooted when you land in the hot spot. Terrific, trying, as well as im kind of gallant i was qualified to fix it under such stress. Those that pass the phone or photo interview move on to the in-person meetings. Once more, it's crafty question, and also not just in damage of functions it out. On the far side allowing myself to get some shouting meemies out, i genuinely delighted in the opportunity to get a better feel for campus/atmosphere. Knowing the really particular response to some very specific SQL meeting questions is great, however it's not going to aid you if you're asked something unanticipated. Don't get me wrong-- targeted prep work can certainly aid.

Note that this not a Not Null constraint and do not confuse the default value restraint with prohibiting the Void entries. The default worth for the column is established only when the row is created for the first time and column worth is ignored on the Insert. Denormalization is a database optimization method for raising a data source framework efficiency by including repetitive information to several tables. Normalization is a data source design technique to arrange tables to decrease data redundancy and also data reliance. SQL restraints are the set of regulations to restrict the insertion, removal, or updating of information in the databases. They restrict the sort of information entering a table for maintaining information accuracy and integrity. CREATE-- Used to create the database or its things like table, index, function, sights, activates, and so on. A unique key is utilized to distinctly recognize each document in a database. A CHECK constraint is utilized to restrict the worths or sort of information that can be kept in a column. A Main trick is column whose worths uniquely recognize every row in a table. The primary function of a main type in a information table is to preserve the interior integrity of a information table. Query/Statement-- They're often used interchangeably, however there's a mild difference. Listed here are https://is.gd/snW9y3 concerns as well as answers that reaffirms your knowledge regarding SQL and also supply new insights as well as learning about the language. Go through these SQL interview inquiries to freshen your expertise prior to any kind of interview. Consequently, your following job won't be about describing what SQL constraints as well as tricks mean in general, although you must be extremely knowledgeable about the idea. You will certainly rather be given the possibility to show your ability to elaborate on a certain sort of an SQL restraint-- the international vital restraint. Write a SQL query to find the 10th tallest optimal (" Altitude") from a " Hill" table. Alteration to the column with VOID worth or perhaps the Insert operation defining the Void worth for the column is enabled. Click on the Establish Primary Trick toolbar switch to set the StudId column as the main vital column. A RIGHT OUTER SIGN UP WITH is one of the SIGN UP WITH procedures that enables you to specify a SIGN UP WITH provision. It preserves the unequaled rows from the Table2 table, joining them with a NULL in the shape of the Table1 table. And then, as presently as we reduced that possibility, everybody broken out laughing however you can't be in on the method." there are many " weak points" that you can become favorable situations to share an response that your interviewer will respect as well as see. - this environments covers the ironware, web servers, operating system, internet browsers, other software program system, and so on. Duties that you were not able-bodied to be full. "i determine which project is near considerable, and then i try to do that project first previously complete the being successful one. Completely instance, there are approach of accounting plan, arsenal bundle, and so on. While it's less complicated to ask generic concerns, you risk not obtaining the selective info you need to make the best hiring resolution. Inquiry optimization is a process in which data source system compares different inquiry approaches and select the question with the least expense. Main vital produced on more than one column is called composite main key. ERASE eliminates some or all rows from a table based on the problem. ABBREVIATE removes ALL rows from a table by de-allocating the memory web pages. The procedure can not be rolled back DECREASE command gets rid of a table from the data source entirely. The main distinction in between both is that DBMS conserves your information as files whereas RDMS saves your info in tabular kind. Also, as the keyword Relational indicates, RDMS allows various tables to have relationships with one another using Main Keys, Foreign Keys etc. This creates a vibrant chain of hierarchy in between tables which also provides handy restriction on the tables. Presume that there are at https://tinyurl.com/c7k3vf9t in the Hill table. That's why leading business are progressively moving far from common concerns as well as are rather offering candidates a crack at real-life interior circumstances. "At Airbnb, we gave prospective hires accessibility to the devices we utilize and also a vetted data collection, one where we understood its limitations and issues. It permitted them to concentrate on the form of the data and structure solution to issues that were significant to us," notes Geggatt. https://geekinterview.net for a certain condition prior to inserting information into a table. If the information passes all the Inspect restraints after that the information will certainly be put right into the table otherwise the information for insertion will certainly be thrown out. Learn More makes sure that all values in a column please specific conditions. A Not Void restriction limits the insertion of void worths right into a column. If we are utilizing a Not Void Constraint for a column after that we can not overlook the value of this column throughout insertion of information right into the table. The default restriction allows you to establish a default value for the column.

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data persistence

What is a data persistence??

Information systems process data and convert it into information. The data should persist for later use

To maintain the status

For logging purposes

To further process and derive knowledge (data science)

Data can be stored, read, updated/modified, and deleted. At run time of software systems, data is stored in main memory, which is volatile (computer storage that only maintains its data while the device is powered (RAM),Data should be stored in non-volatile storage for persistence(Hard disk)

              Two main ways of storing data

Files

Databases, in here many formats for storing data.

Plain Text

JSON

Tables

Text files

Images

What is a Data, Database, Database Server, Database Management System??

Data: In computing, data is information that has been translated into a form that is efficient for movement or processing

Data Types

Database: A database is a collection of information that is organized so that it can be easily accessed, managed and updated

Database types

Hierarchical databases: data is stored in a parent-children relationship nodes. In a hierarchical database, besides actual data, records also contain information about their groups of parent/child relationships.

Network databases: Network database management systems (Network DBMSs) use a network structure to create relationship between entities. Network databases are mainly used on a large digital computer.

Relational databases: In relational database management systems (RDBMS), the relationship between data is relational and data is stored in tabular form of columns and rows. Each column if a table represents an attribute and each row in a table represents a record. Each field in a table represents a data value.

Non-relational databases (NoSQL)

Object-oriented databases: In this Model we have to discuss the functionality of the object-oriented Programming. It takes more than storage of programming language objects.

Graph databases: Graph Databases are NoSQL databases and use a graph structure for sematic queries. The data is stored in form of nodes, edges, and properties.

Document databases: Document databases (Document DB) are also NoSQL database that store data in form of documents. Each document represents the data, its relationship between other data elements, and attributes

Database Server: The term database server may refer to both hardware and software used to run a database, according to the context. As software, a database server is the back-end portion of a database application, following the traditional client-server model. This back-end portion is sometimes called the instance. It may also refer to the physical computer used to host the database. When mentioned in this context, the database server is typically a dedicated higher-end computer that hosts the database.

Database Management System: A database management system (DBMS) is system software for creating and managing database. The DBMS provides users and programmers with a systematic way to create, retrieve, update and manage data.

 Files and databases

Advantages of storing data in files

Higher productivity

Lower costs

Time saving

Disadvantages of storing data in files

Data redundancy

Data inconsistency

Integrity problem

Security problem

Advantages of storing data in database

Excellent data integrity independence from application programs

Improve data access to users through the use of hos and query language

Improve data security storage and retrieval

Disadvantages of storing data in database

Complex, difficult and time consuming to design

Substantial hardware and software start-up cost.

Initial training required for all programmers and users

Data arrangements

Un-structured - Unstructured data has internal structure but is not structured via pre-defined data models or schema. It may be textual or non-textual, and human- or machine-generated. It may also be stored within a non-relational database like NoSQL

           E.g. – paragraph, essay

Semi- structured - Semi-structured data is a data type that contains semantic tags, but does not conform to the structure associated with typical relational databases. Semi-structured data is one of many different types of data.

Structured - Structured data is data that has been organized into a formatted repository, typically a database, so that its elements can be made addressable for more effective processing and analysis. This persistence technique is better for these arrangements.

                                 Data Warehouse is an architecture of data storing or data repository. Whereas Big Data is a technology to handle huge data and prepare the repository. ... Data warehouse only handles structure data (relational or not relational), but big data can handle structure, non-structure, semi-structured data.

APPLICATION TO FILES/DB

Files and DBs are external components.They are existing outside the software system. Software can connect to the files/DBs to perform CRUD operations on data  

File –File path, URL

DB –connection string

To process data in DB ,

SQL statements

Statement interface is used to execute normal SQL queries. You can’t pass the parameters to SQL query at run time using this interface. This interface is preferred over other two interfaces if you are executing a particular SQL query only once. The performance of this interface is also very less compared to other two interfaces. In most of time, Statement interface is used for DDL statements like CREATE, ALTER, DROP etc. For example,

 //Creating The Statement Object

Statement stmt = con.createStatement();

//Executing The Statement

      stmt.executeUpdate("CREATE TABLE STUDENT(ID NUMBER NOT NULL, NAME VARCHAR)");

 Prepared statements

Prepared Statement is used to execute dynamic or parameterized SQL queries. Prepared Statement extends Statement interface. You can pass the parameters to SQL query at run time using this interface. It is recommended to use Prepared Statement if you are executing a particular SQL query multiple times. It gives better performance than Statement interface. Because, Prepared Statement are precompiled and the query plan is created only once irrespective of how many times you are executing that query. This will save lots of time.

//Creating PreparedStatement object

  PreparedStatement pstmt = con.prepareStatement("update STUDENT set NAME = ? where ID = ?");

  //Setting values to place holders using setter methods of PreparedStatement object

  pstmt.setString(1, "MyName");   //Assigns "MyName" to first place holder

          pstmt.setInt(2, 111);     //Assigns "111" to second place holder

 //Executing PreparedStatement

 pstmt.executeUpdate();

 Callable statements

Callable Statement is used to execute the stored procedures. Callable Statement extends Prepared Statement. Usng Callable Statement, you can pass 3 types of parameters to stored procedures. They are : IN – used to pass the values to stored procedure, OUT – used to hold the result returned by the stored procedure and IN OUT – acts as both IN and OUT parameter. Before calling the stored procedure, you must register OUT parameters using registerOutParameter() method of Callable Statement. The performance of this interface is higher than the other two interfaces. Because, it calls the stored procedures which are already compiled and stored in the database server.

 /Creating CallableStatement object

 CallableStatement cstmt = con.prepareCall("{call anyProcedure(?, ?, ?)}");

 //Use cstmt.setter() methods to pass IN parameters

 //Use cstmt.registerOutParameter() method to register OUT parameters

 //Executing the CallableStatement

 cstmt.execute();

 //Use cstmt.getter() methods to retrieve the result returned by the stored procedure

  Useful objects

Connection

Statement

Reader

Result set

 OBJECT RELATIONAL MAPPING (ORM)

There are different structures for holding data at runtime  

Application holds data in objects

Database uses tables (entities)

Mismatches between relational and object models

Granularity: Object model has more granularity than relational model.

Subtypes: Subtypes (means inheritance) are not supported by all types of relational databases.

Identity: Like object model, relational model does not expose identity while writing equality.

Associations: Relational models cannot determine multiple relationships while looking into an object domain model.

Data navigation: Data navigation between objects in an object network is different in both models

Beans use POJO  

stands for Plain Old Java Object. It is an ordinary Java object, not bound by any special restriction other than those forced by the Java Language Specification and not requiring any class path. POJOs are used for increasing the readability and re-usability of a program. POJOs have gained most acceptance because they are easy to write and understand. They were introduced in EJB 3.0 by Sun microsystems.

A POJO should not:

Extend pre-specified classes.

Implement pre-specified interfaces.

Contain pre-specified annotations.

Beans

•Beans are special type of Pojos. There are some restrictions on POJO to be a bean. All JavaBeans are POJOs but not all POJOs are JavaBeans. Serializable i.e. they should implement Serializable interface. Still some POJOs who don’t implement Serializable interface are called POJOs because Serializable is a marker interface and therefore not of much burden. Fields should be private. This is to provide the complete control on fields. Fields should have getters or setters or both. A no-AR constructor should be there in a bean. Fields are accessed only by constructor or getter setters.

POJO/Bean to DB

Java Persistence API (JPA)

An API/specification for ORM.

Uses  

POJO classes

XML based mapping file (represent the DB)

A provider (implementation of JPA)

 JPA Architecture

JPA implementations

Hybernate

JDO

EclipseLink

ObjectDB

  NOSQL AND HADOOP

Not Only SQL (NOSQL)

Relational DBs are good for structured data.For semi-structured and un-structured data, some other types of DBs can be used

Key-value stores

Document databases

Wide-column stores

Graph stores

  Benefits of NoSQL

When compared to relational databases, NoSQL databases are more scalable and provide superior performance, and their data model addresses several issues that the relational model is not designed to address:

Large volumes of rapidly changing structured, semi-structured, and unstructured data.

 NoSQL DB servers

MongoDB

Cassandra

Redis

Amazon DynamoDB

Hbase

 Hadoop

           The Apache Hadoop software library is a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models. It is designed to scale up from single servers to thousands of machines, each offering local computation and storage. Rather than rely on hardware to deliver high-availability, the library itself is designed to detect and handle failures at the application layer, so delivering a highly-available service on top of a cluster of computers, each of which may be prone to failures.

  Hadoop core concepts

Hadoop Distributed File System (HDFS™): A distributed file system that provides high-throughput access to application data

Hadoop YARN: A framework for job scheduling and cluster resource management.

Hadoop Map Reduce: A YARN-based system for parallel processing of large data sets.

INFORMATION RETRIEVAL

Data in the storages should be fetched, converted into information, and produced for proper use

Information is retrieved via search queries

                       Keyword search

                       Full-text search

The output can be

                      Text

                       Multimedia