Unix-based operating systems, such as Linux and macOS, offer a powerful command-line interface that allows users to interact with the system in a text-based environment. Understanding and utilizing Unix commands can greatly enhance your productivity and efficiency. In this blog post, we will explore 10 of the most common and useful Unix commands that every user should know. Whether you’re a beginner or an experienced user, these commands will prove valuable in your day-to-day tasks.
ls – List Files and Directories: The “ls” command is used to list the files and directories in the current directory. It provides useful information like file names, sizes, permissions, and timestamps. Adding options such as “-l” (long format) and “-a” (including hidden files) can further enhance the output.
cd – Change Directory: The “cd” command allows you to navigate between directories. Using “cd” followed by a directory path will change your current working directory to the specified location. For example, “cd Documents” will take you to the “Documents” directory.
mkdir – Create Directories: Need to create a new directory? The “mkdir” command is here to help. Simply type “mkdir” followed by the desired directory name, and a new directory will be created in the current location.
cp – Copy Files and Directories: The “cp” command is used to copy files and directories from one location to another. You need to specify the source file/directory and the destination where you want to copy it. For instance, “cp file.txt /path/to/destination” will copy “file.txt” to the specified destination.
rm – Remove Files and Directories: To delete files or directories, the “rm” command is your go-to tool. Be cautious when using it, as it permanently removes files without any confirmation. To remove a file, simply type “rm file.txt”. For directories, you can use the “-r” option to remove them recursively, as in “rm -r directory”.
mv – Move and Rename Files and Directories: The “mv” command allows you to move files and directories from one location to another, as well as rename them. To move a file, specify the source and destination locations. To rename a file, provide the current name followed by the desired new name.
grep – Search Within Files: When you need to search for specific content within files, “grep” is the command to use. It searches for a given pattern or text within one or multiple files. You can combine it with other commands to perform powerful text processing operations.
man – Access Manual Pages: The “man” command provides access to the extensive Unix manual pages. By typing “man” followed by a command or topic, you can retrieve detailed information about its usage, options, and examples. This is particularly useful for learning about new commands and exploring their functionalities.
chmod – Change File Permissions: Unix-based systems have a robust permissions system that determines who can read, write, or execute files. The “chmod” command allows you to change these permissions. By specifying the appropriate permissions using numeric codes or symbolic representations, you can control file access effectively.
ssh – Securely Connect to Remote Servers: The “ssh” command enables secure remote connections to other Unix-based servers or machines. By typing “ssh username@hostname”, you can establish a secure shell session and execute commands on the remote system. This is widely used by system administrators and developers for remote management and file transfer.
welcome back to shortlearner.com interview preparation series. Today in this series we will share most asked tableau interview questions and answer for beginner and experienced candidate.
most of our visitors have a query How do I prepare for a tableau interview? , What questions are asked in a data analyst interview? , How do I prepare for a data analyst interview? and many more interview and preparation related questions.
So we are collected most asked tableau interview questions after consulting with top industry experts in the field of Data analytics and visualization.
Q1. What is Tableau ?
Tableau is one of the most popularly used BI tools across the globe.
Tableau is a data visualization tool that allows the user to develop an interactive and visualization in the form of dashboards, worksheets for the betterment of the business
Q2. What are the five main products offered by Tableau?
Q3. What is the latest version of Tableau Desktop?
For Tableau Desktop, the most recent release upgrade was from Tableau 2021.3 to Tableau 2021.4; the one before that was from Tableau 2021.2 to Tableau 2021.3.
Q4. How many type of file extension in Tableau ?
There are many file types and extensions in Tableau. Some of the file extensions in Tableau are:
Tableau Workbook (.twb).
Tableau Packaged Workbook (.twbx).
Tableau Datasource (.tds).
Tableau Packaged Datasource (.tdsx).
Tableau Data extract (.tde).
Tableau Bookmark (.tdm).
Tableau Map Source (.tms).
Tableau Preferences (.tps).
Q5. What is the different between twb and twbx file extensions.
The file extension .twb is a live connection; it points to the data source. The user receiving .twb needs permission to access the said data source and no data is included. On the other hand, .twbx takes the data offline and stores it as a package or zip-like file, thereby eradicating the need for permissions.
Q6. What is the maximum number of tables we can join in Tableau?
We can join a maximum of 32 tables; it is not possible to combine more than 32 tables.
Q.7 What are the different datatypes in Tableau?
Tableau Data Types gives us information about the kind of data stored in the data source. There can be a text value, data value, time value, Boolean value, etc. Tableau supports Data Types such as Boolean, String, Date & Date time, and Number.
Dimensions: A dimension table ,having reference of a product key form the table, can consist of product name, product type, size, color, description, etc.
Measures: are the numeric metrics or measurable quantities of the data, which can be analyzed by dimension table. Measures are stored in a table that contain foreign keys referring uniquely to the associated dimension tables.
Q.9 What are shelves?
They are Named areas to the left and top of the view. You build views by placing fields onto the shelves. Some shelves are available only when you select certain mark types.
Q10. What are the different connections you can make with your dataset?
We can either connect live to our data set or extract data onto Tableau.
Live: Connecting live to a data set leverages its computational processing and storage. New queries will go to the database and will be reflected as new or updated within the data.
Extract: An extract will make a static snapshot of the data to be used by Tableau’s data engine. The snapshot of the data can be refreshed on a recurring schedule as a whole or incrementally append data. One way to set up these schedules is via the Tableau server.
The benefit of Tableau extract over live connection is that extract can be used anywhere without any connection and you can build your own visualization without connecting to database.
Q11. Define different parameters in Tableau and their working?
The Tableau parameters are dynamic variables or dynamic values that replace the constant values in data evaluation and filters. The user can create an evaluated field value that returns true when the score pars the 80, and otherwise false.
Q12. What is data visualization?
Data visualization refers to the techniques used to communicate data or information by encoding it as visual objects (e.g. points, lines, or bars) contained in graphics.
Data visualization is a demonstration if the information in a pictorial or graphical form. It empowers decision makers to have look analytics presented visually, so they can get a handle on challenging ideas or create new patterns. With intelligent visualization, you can make the idea a stride further by utilizing technology to draw them into diagrams and charts for more detail.
Q13. Why did we choose data visualization?
Data visualization is a fast, simple to pass on ideas universally and you can explore different scenarios by making slight alterations. As a human being processes data by utilizing graphs or charts to have a look of complex information is quit easier rather than looking out them on spreadsheets or reports.
Q14. Distinguish between parameters and filters in Tableau?
The parameters allow users to insert the values, which can be integers, float, date, string that can be used in calculations. The filters only receive values users choose to ‘filter by’ the list, which cannot be used to calculate. The users can dynamically change the dimensions and measures in parameter but filters do not approve the feature.
Q15. What are Filters? How many types of Filters are there in Tableau?
This is one of the most frequently Tableau developer interview questions asked for the tableau developer. A Filter restricts unnecessary data, it shows the exact data we want. there are 3 types of filters in tableau.
Normal Filter is used to restrict the data from database based on selected dimension or measure. A Traditional Filter can be created by simply dragging a field onto the ‘Filters’ shelf.
Quick filter is used to view the filtering options and filter each worksheet on a dashboard while changing the values dynamically (within the range defined) during the run time.
Context Filter is used to filter the data that is transferred to each individual worksheet. When a worksheet queries the data source, it creates a temporary, flat table that is uses to compute the chart. This temporary table includes all values that are not filtered out by either the Custom SQL or the Context Filter.
Q16. Where can you use global filters?
Global filters can be utilized as a part of sheets, dashboards and in stories.
Q17. What are context filters and state the limitations of context filter?
Context filter: Tableau helps in making the filtering process straightforward and easy. It does so by creating a hierarchy of filtering, where all the other remaining filters that are present refer to the context filter for all their subsequent operations.
Thus, the remaining filters will now process the data, that is already passed through the context filter. Development of one or more context filters helps in improving the performance, as the users do not have to create extra filters on the large data source, which actually reduces the query-execution time.
Limitations of context filter: Generally, Tableau takes a little time for placing a filter in context. In case the filter is set as a context one then the software develops a temporary table for that specific context filter. This table reloads each time and consists of all the variables and values that are not filtered by context or custom SQL filter.
Q18. What is the Context Filter?
Context filter is an extremely productive filter from all of the filters in Tableau. It enhances the performance in Tableau by making a Sub-Set of information for the filter selection. Context Filters serve two principal purposes.
Improves execution: If you set a lot of filters or have an expansive information source, the inquiries can be slow. You can set at least one context filters to enhance the execution. Develops top N filter you could set a context filter to incorporate just the data of interest, and after that set a numerical or a best N filter.
Q19. Explain the aggregation and disaggregation of data in Tableau ?
Aggregation and disaggregation of data in Tableau are the ways to develop a scatterplot to measure and compare the data values.
Aggregation:It is calculated the form of a set of values that return a single numeric value. A default aggregation can be set for any measure which is not user-defined.
Disaggregation:The disaggregation of data refers to view each data source row during analyzing of data both dependently and independently.
Q20. What are the extracts and schedules in Tableau server?
First copies or subdivisions of the actual data from the original data source are called data extract. The workbooks which use the data extracts instead of using live DB connections are faster and the extracted data is imported into Tableau engine.
Later after the extraction of data the users can publish the workbooks which publish the extracts in Tableau server. And, the scheduled refreshers are the scheduling tasks which are already set for data extract refresh so that they get refreshed automatically while a workbook is published with data extraction.
Q21. How do you define a dashboard?
A dashboard is an information management device that visually tracks, analyzes and shows key performance indicators (KPI), measurements and main points which focus on the screen to monitor the health of a business, division or particular process. They are adaptable to meet the particular needs of a department and company. A dashboard is the most proficient approach to track numerous data sources since it gives a central area to organizations to screen and examine performance.
Q22. Mention and explain some components on the dashboard?
Some of the dashboard components are: Horizontal component: In the dashboard the horizontal component’s containers allow the designer to combine the worksheets and dashboards components from left to right across the user’s page and the height of the elements are edited at once.
Vertical component: In the dashboard Vertical component’s containers allows the user to combine the worksheets and dashboard components from left to right across the user’s page and the width of the elements are edited at once.
Text: It is an alphabetical order.
Image Extract: A Tableau is in XML format. In case of extracting images, the Tableau applies the codes to extract an image can be stored in XML.
Web [URL ACTION]: A Web URL action is a certain type of hyperlink that directs to a web page always or to any other web-based resource that is residing outside of Tableau. The user can hence use the URL actions for linking up of more information about the user’s data, which might be hosted outside of the user’s data source. In order make the link relevant to the user data, the user can substitute field values of a selection into the URL as parameters.
Q23. What is data blending in tableau?
Data blending in Tableau is used when there is associated data in multiple data sources, which you want to analyze together in a single window. To exemplify, consider the Sales data in a relational database and Sales Target data in a spreadsheet, to compare, you can blend the data based on shared dimensions to get access to the Sales Target measure. The two sources involved in data blending are mentioned as primary and secondary data sources. A left join is formed between the primary data source and the secondary data source with all the data rows from primary and agreeing data rows from a secondary data source.
Q24. What is the difference between joining and blending in Tableau?
Joining term is used when you are combining data from the same source, for example, worksheet in an Excel file or tables in Oracle database
While blending requires two completely defined data sources in your report.
Q25. What is dual axes?
Dual Axis is an excellent phenomenon supported by Tableau that helps users view two scales of two measures in the same graph. Many websites like Indeed.com and other make use of dual axis to show the comparison between two measures and their growth rate in a septic set of years. Dual axes let you compare multiple measures at once, having two independent axes layered on top of one another. This is how it looks like
Welcome back to shortlearner.com, in this post we will see how to enable PHP ZIP extension on cPanel. before start this tutorial, we should take a overview about PHP extension. so basically PHP extension enables you to transparently read or write ZIP compressed archives and the files inside them.
and most of the time it is disable by default in cPanel , so we have to manually install it. So just follow the steps and install these extensions manually. Note: try to follow snaps for better understanding.
step 1: So in the very first step , we should login into our cPanel(Control Panel) and than go to the software section Step 2: in the software section click on PHP Pear Packages
Step3: after clicking on PHP Pear Packages we are searching our ZIP extension and install it.
step 4 : After installing the package we should again go to our software section and click on the PHP version .
Step5: once we click on the select PHP Version, we can see all the enable extension over there, and we can see our Archiv_ZIP as well. so we just checked it and hit on the save button to add archive_zip in our current PHP version.
Step5: now the last and very important step we will follow to complete this tutorial.again go to the software section and click on the PHP processes and hit the kill process button.
Now we can use your PHP ZIP Extension our website.
Welcome back to shortlearner.com, today in this post we will see how to install XAMPP server in our windows system.
XAMPP is a popular open-source software package that is used to create and run web servers on a local machine. It allows you to develop and test web applications without needing an internet connection or hosting service. In this blog, we will guide you through the process of installing XAMPP on your local system.
Step 1: Download XAMPP The first step is to download XAMPP from the official website. Go to https://www.apachefriends.org/index.html and click on the download button. You will see options for different operating systems like Windows, Mac, and Linux. Select the one that matches your system and download the file.
Step 2: Install XAMPP
Once you have downloaded the XAMPP installer, double-click on the downloaded file to start the installation process. Follow the on-screen instructions to complete the installation. You may be asked to select the components you want to install, such as Apache, MySQL, PHP, and Perl. Choose the ones you need and click on the Next button.
Step 3: Start the XAMPP Control Panel
After the installation is complete, you can start XAMPP by running the XAMPP Control Panel. This application allows you to start and stop the Apache and MySQL servers, as well as configure other settings. To open the control panel, go to the XAMPP folder in your program files and double-click on the “xampp-control.exe” file.
Step 4: Configure Apache and MySQL
Before you can start using XAMPP, you need to configure Apache and MySQL. Open the XAMPP Control Panel and click on the “Start” button next to Apache and MySQL. Once the servers have started, you can access them by typing “http://localhost” in your web browser. If everything is working correctly, you should see the XAMPP home page.
Step 5: Test Your Setup
To test your XAMPP setup, create a new file in the “htdocs” folder. This is the default location for your web files, and Apache will automatically serve files from this folder. Create a new file named “index.php” and add the following code:
<?php
echo "Hello, world!";
?>
Save the file and go to “http://localhost/index.php” in your web browser. If everything is working correctly, you should see the text “Hello, world!” displayed on the page.
In conclusion, installing XAMPP on your local system is a simple process that can be done in a few easy steps. By following the steps outlined in this blog, you should be able to install XAMPP and start using it to develop and test web applications on your local machine.
Following are mostly asked Tableau MCQ test that are designed for professionals like you to crack you interviews. You can take this Tableau online test before appearing to you real interview. This Tableau quiz there are around 30+ multiple choice questions on Tableau with four options.
Tableau is the Business Intelligence tool for analyzing the data. It can connect to files, relational and Big Data sources to acquire and process the data. The software allows real-time collaboration and data blending, which makes it unique. It is also positioned as a leader Business Intelligence and Analytics Platform in the Gartner Magic Quadrant. Businesses and many government organizations use tableau for visual data analysis. Contenders need to learn all the fundamentals of the Tableau to score marks in the interviews. By brushing up all the topics regarding Tableau, the candidates can quickly answer the questions.
Welcome back to shortlearner.com, in this post we will see how get URL and URL parameters with the help of JavaScript functionality. People also asked how to Get the values from the “GET” parameters (JavaScript), Most of the time we need to fetch the parameters from URL.
get-url-parameter-in-js
so here we are taking a URL with having some parameters and will separate the param from the URL with some pre defined JavaScript functions. JavaScript can access the current URL in parts. For this Link:
If you need to break up up the pathname, for example, a full website address like http://localhost/wordpress/blah/blah/blah/index.php, you can split the string on “/” characters.
var pathArray = window.location.pathname.split('/');
Then access the different parts by the parts of the array, like
var secondLevelLocation = pathArray[0];
To put that pathname back together, you can stitch together the array and put the “/” back in:
var newPathname = "";
for (i = 0; i < pathArray.length; i++) {
newPathname += "/";
newPathname += pathArray[i];
}
Intermediate level interview question for tableau developer.
Q. What are the sets?
Sets are custom fields that are created within Tableau Desktop and define a subset of data based on some conditions within Tableau Desktop based on. A set can be based on a computed condition, for example, a set can be created for having a subset data of top 10 employees with the highest salary.
Q. what are groups.?
tableau group is basically set of multiple members combined in a single dimension to create a higher category of the dimension. For example, if you are working with a view that shows average basic salary by major, you may want to group certain majors together to create major categories.
Q. How to use groups in a calculated field?
Add the ‘GroupBy’ clause to SQL queries or create a calculated field in the data window to group fields.
Using groups in a calculation. You cannot reference ad-hoc groups in a calculation.
Blend data using groups created in the secondary data source: Only calculated groups can be used in data blending if the group was created in the secondary data source.
Use a group in another workbook. You can easily replicate a group in another workbook by copy and pasting a calculation.
Q. what are the difference between groups and sets in tableau.?
this is the most asked tableau interview questions, and you should prepare answer of this question with real world problem. Sets
sets are custom fields that define a subset of data based on some conditions IN/OUT.
No provision of creating custom territories using sets.
sets get positioned only in the data pane under sets section.
sets differentiate the data in the viz , through IN/OUT notations without aggregating the data.
sets are dynamic(as well as static).
Groups:
a group is a collection of related memebers in field.
custom territories are accomplished using groups.
tableau generates a new entry in the data source as well as dimensions section when a new group is created.
groups aggregate the data.
groups are only static.
Q. What is the difference between discrete and continuous in Tableau?
There are two types of data roles in Tableau – discrete and continuous dimension.
Discrete data roles are values that are counted as distinct and separate and can only take individual values within a range. Examples: number of threads in a sheet, customer name or row ID or State. Discrete values are shown as blue pills on the shelves and blue icons in the data window.
Continuous data roles are used to measure continuous data and can take on any value within a finite or infinite interval. Examples: unit price, time and profit or order quantity. Continuous variables behave in a similar way in that they can take on any value. Continuous values are shown as green pills.
Q. What is the difference between a tree and heat map?
Both the maps help in analyzing data. While a heat map visualizes and compares different categories of data, a treemap displays a hierarchical structure of data in rectangles. Heat map visualizes measures against dimensions by depicting them in different colors. Similar to a text table with values defined in different colors.
Heat Map: A heat map can be used for comparing categories with color and size. With heat maps, you can compare two different measures together.
Heatmap-in-Tableau
Tree Map: A tree map also does the same except it is considered a very powerful visualization as it can be used for illustrating hierarchical data and part-to-whole relationships.
Tree-Map-In-Tableau
Q. what is the difference between published data sources and embedded data sources in Tableau?
The difference between published data source and embedded data source is that,
Published data source: It contains connection information that is independent of any workbook and can be used by multiple workbooks.
Embedded data source: It contains connection information and is associated with a workbook.
Q. How to create a calculated field in Tableau?
Click on the drop down to the right of Dimensions on the Data pane and select “Create > Calculated Field” to open the calculation editor.
Name the new calculated field and create a formula. Take a look at the example below
Q. Mention what are different Tableau files?
Different Tableau files include:
Workbooks: Workbooks hold one or more worksheets and dashboards
Bookmarks: It contains a single worksheet and its an easy way to quickly share your work
Packaged Workbooks: It contains a workbook along with any supporting local file data and background images
Data Extraction Files: Extract files are a local copy of a subset or entire data source
Data Connection Files: It’s a small XML file with various connection information
Q. What are the different types of joins in Tableau?
Tableau is pretty similar to SQL. Therefore, the types of joins in Tableau are similar:
Left Outer Join: Extracts all the records from the left table and the matching rows from the right table.
Right Outer Join: Extracts all the records from the right table and the matching rows from the left table.
Full Outer Join: Extracts the records from both the left and right tables. All unmatched rows go with the NULL value.
Inner Join: Extracts the records from both tables.
Q. How to remove ‘All’ options from a Tableau auto-filter?
The auto-filter provides a feature of removing ‘All’ options by simply clicking the down arrow in the auto-filter heading. You can scroll down to ‘Customize’ in the dropdown and then uncheck the ‘Show “All” Value’ attribute. It can be activated by checking the field again.
Q. What is the DRIVE Program Methodology?
DRIVE program methodology creates a structure around data analytics derived from enterprise deployments. The drive methodology is iterative in nature and includes agile methods that are faster and effective.
Q. What is Tableau data engine.?
An analytical database that computes instant query responses, predictive analysis of the server, and integrated data. The data engine is useful when you need to create, refresh, or query extracts. It can be used for cross-database joins as well.
Q. How do you embed views into webpages?
You can easily integrate interactive views from your Tableau Server or Tableau online onto webpages, blogs, web applications, or internet portals. But to have a look at the views, the permissions demand the viewer to create an account on the Tableau Server. To embed views, click the Share button on the top of the view and copy the embed code to paste it on the web page. You can also customize the embedded code or Tableau JavaScript APIs to embed views.
Q. What is data blending in Tableau?
Data blending in Tableau is used when there is associated data in multiple data sources, which you want to analyze together in a single window. To exemplify, consider the Sales data in a relational database and Sales Target data in a spreadsheet, to compare, you can blend the data based on shared dimensions to get access to the Sales Target measure.
The two sources involved in data blending are mentioned as primary and secondary data sources. A left join is formed between the primary data source and the secondary data source with all the data rows from primary and agreeing data rows from a secondary data source.
Q. What is Tableau reader?
Tableau Reader is a desktop app that was developed to be used for opening and interacting with data visualizations. Tableau reader was created when Tableau was still starting up and it is a free product. It helps an organization in governing how analytic content is to be shared and distributed.
Content creators and analyst makes use of this free application to distribute the contents they developed in Tableau desktop. Tableau reader was once the only option for sharing and distributing interactive content with others that need it within a group. This was possible even without having access to Tableau Desktop.
Q. what is stacked bar chart?
stacked bar chart is used to show comparison between categories of data, but with ability to break down and compare parts of whole.
Q. What is a Gantt chart?
A Gantt chartis a valuable graphical device, which demonstrates tasks or activities performed against time. It is also called the visual presentation of a task where the activities are separated and shown on a chart, which makes it is straightforward and interpret.
Q. What is a Histogram chart?
A histogram is a plot that gives you a chance to find, and show, the basic frequency (shape) of an arrangement of continuous information. This allows the examination of the information for its hidden distribution, anomalies, sleekness, and so on.
Q. what is waterfall chart in tableau.?
A waterfall chart is a type of information perception that helps in understanding the total impact of consecutively presented positive or negative values. These values can either be time-dependent or category based. The waterfall chart is known by another name, which is called a flying bricks graph or Mario outline because of the obvious suspension of sections (bricks) in mid-air.
Q. How Can You Display the Top Five and Bottom Five Sales in the Same View?
You can see top five and bottom five sales with the help of these functions:
Drag ‘customer name’ to row and sales to the column.
Sort Sum(sales) in descending order.
Create a calculated field ‘Rank of Sales’.
Q. How to do Performance Testing in Tableau?
Performance testing is again an important part of implementing tableau. This can be done by loading Testing Tableau Server with TabJolt, which is a “Point and Run” load generator created to perform QA. While TabJolt is not supported by tableau directly, it has to be installed using other open source products.
