Tableau Interview Questions Set 10
1. what is Assume referential integrity?A. In Database terms every row in fact table will contain a combination row in dimension table.
Using this method only we build Primary and Foreign Keys for joining 2 tables.
The same option is even available in table under File Menu --> Data --> Assume Referential Integrity.
If you unable this option for a .tds then tableau intelligently queries the tables and reduces the query retrieval time.
By selecting Assume Referential Integrity, you tell Tableau that the joined tables have referential integrity.
In other words, you are confirming that the fact table will always have a matching row in the Dimension table.
Because that is true, Tableau doesn't need any information from the Dimension table in order to return these results.
When you drag any fact column (Ex:AmountSales) field into the view, Tableau can simplify the query just with Fact Column.
2.What is Pageshelf?
A.The Pages shelf lets you break a view into a series of pages so you can better analyze how a specific field affects the rest of the data in a view.
Ex: Drag&Drop Year column in page shelf, you will see drop down with list of year val if you select a value then it will take you to page contains selected year value.
3.what is default Data Blending Join?
A.No Join condition is not available while Data Blending,but default will be Inner Join.
4.Max no.of records in a Table?
A.Which table you mean in a database table.
If so 'n' number of rows and 255 columns.
5.Difference between scattere plot vs Tree map?
A. TreeMaps:
Treemaps let you display data in nested rectangles.
You use dimensions to define the structure of the treemap, and measures to define the size or color of the individual rectangles.
Treemaps are a relatively simple data visualization that can provide insight in a visually attractive format.
Treemaps cannot accommodate more than two measures—one to control size, the other to control color.
Treemaps can accommodate any number of dimensions, but you can only use one dimension to diversify the view, by dragging it to Color.
Other dimensions can be used only to multiply the number of rectangles in the view.
Dimensions cannot be displayed in a hierarchy. We can not add the Trend Line in Tree Maps
Scatter Plot:
Scatter plots provide an easy way to visualize relationships between numerical variables.
In Tableau, you create a scatter plot by placing at least one measure on the Columns shelf and at least one measure on the Rows shelf.
We can add the trend lines in Scatter Plot and we can show dimensions in hierarchy.
6.Types of filters?
A.Database,Context,Query,Quicks Filters
Normal Filter Quick Filter Data Source Filter Context Filter
7.types of annotations?
A.The Annotation is a message that can be displayed for a mark/object.We have 3 namely
Mark,Point and Area
Process: Right click on object,point or area and select --> "Annotate" --> Mark or Area or Point.
8.how to change null values as n/a in view?
A. We can handle the Null Values in 3 ways
1.Using Filter we can eliminate the Null Values.
2.Using Axis-->Format--> Marks --> Hide option we can hide the "Null values".
3.We can also use a calculated field to convert Nulls to Zeros using "IsNull" function.
Ex:IIF(ISNULL([Actual] ), 0, [Actual] )
4.Double click on null Values
9.Recently Tablaeau released Tableau 9.0 Beta. These are the some features..Im posting if u find any is missing please write in to this.
A. Here are some of the features which are going to be in Tableau's next release. Anyone wants to add some more points into this?
Visual Analytics a) Type-in shelves b) Freeform Calculation c) Drag & Drop Calculation d) New Calculation Editor e) Instant reference line & trend line f) Interactive Table calculation editing g) Geographic Search h) Lasso & Radial Selection
Speed (3-4 times faster than current version) a) Multicore Query Execution b) Vector Operations Support c) Parallel Queries d) Continuous Tooltips e) Responsive Pan & Zoom f) Persisted Query Cache
Data Preparation a) Un pivoting b) Web Service API Connector c) Splitting of Data automatically
Story Telling a) Larger Caption b) Background Colors
Enterprise a) Now on server with a simple ease you can provide credentials to different business users on fly b) Server will be more secure & faster
Cloud a) In Tableau Online we can connect directly with the cloud data sources like redshift.
Mobile a) Tableau has started a program for mobile users & they named it as “Project Elastic”. b) It is more faster & user friendly c) Now you do not need internet connection for running your dashboard on mobile or tablets.
10. Lets say we have a dimension called customer name and measure called profit. What is the logic for the condition " If the customer name is "ABC" then sow average of profit"
A.IF ATTR(CustomerName)='ABC' THEN AVG(Profit) END
11. Tableau - difference between groups and sets? You can combine several dimension members into a single member using groups. For example, if you are working with a field that contains thousands of products, you can use Groups to combine those products into higher level categories. Grouping data is also really useful for cleaning up data inconsitencies. For example, your data may have California listed as CA, California, and Calif. When you try to see all sales in California your numbers will be split across these three rows. You can quickly group these three variants together to treat them as a single value. and Sets are custom fields that define a subset of data based on some conditions. A set can be based on a computed condition, for example, a set may contain customers with sales over a certain threshold. Computed sets update as your data changes. Alternatively, a set can be based on specific data point in your view. You can use sets to compare and ask questions about a subset of data. For example, in a scatter plot showing product sales, you may select the products with the most sales and add them to a set. You may then create another set that contains the products with the highest return rates. With these two sets you can ask questions like "What percent of my total sales is from high returned products?" Or you may go further and compare the two sets to each other to create a new set that contains only high sales products that are also returned frequently. 12. How to display state borders for a country by geo coding? go to Maps - Map clik on maps -you will finds 3 options-Map Layer Data Layer Options-May Layer check the border of country
13. Tableau - how we will get three pie charts in a row create dash board with three pi chart.( each for department ,regions and product.) or Better to create 3 individual pie charts and keep them in an order by floating or Tiled in dashboard. 14. Tableau - Aggregation & Disaggregation Aggregate means: SUM(Sales)
Disaggregate means: Sales
15.
1). Who are the founders of Tableau?
Ans: The Company was founded in Mountain View, California in January, 2003 by Chris Stolte, Christian Chabot and Pat Harahan.
2). what are the five main product offered by Tableau company?
Ans: Tableau offers five main products: Tableau Desktop, Tableau Server, Tableau Online, Tableau Reader and Tableau Public.
3). What is the current latest version of Tableau Desktop(as of Feb. 2015)?
Ans: Current versions: Tableau Desktop version 9
4). what is data visualization?
Ans: 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.
5). what is Tableau Desktop?
Ans: Tableau Desktop is based on breakthrough technology from Stanford University that lets you drag drop to analyze data. it is great data visualization tool, You can connect to data in a few clicks, then visualize and create interactive dashboards with a few more.
6). Why tableau?
Ans: Whether your data is in an on-premise database, a database, a data warehouse, a cloud application or an Excel file, you can analyze it with Tableau. You can create views of your data and share it with colleagues,
Customers and partners. You can use Tableau to blend it with other data. And you can keep your data up to date automatically
7). What are the differences between Tableau Software, Good Data and Traditional BI (Business Objects, etc.)?
Ans: rviewquestionspdf.com/2015/05/tableau-interview-question-what-are.html </a>
8). what are Filters? How many types of filters are there in Tableau?
Ans: Filter is nothing but it is restricted to unnecessary, it is showing exact data. Basically filters are 3 types.
1. Quick filter
2. Context filter
3. Data source filter
9). what is disaggregation and aggregation of data?
Ans: http://www.interviewquestionspdf.com/2015/05/tableau-interview-question-what-is.html
10). what is the difference between context filter to other filters?
Ans: Whenever we create context filter Tableau will create a temporary table for this particular filter set and other filters will be apply on context filter data like cascade parameters.. suppose we have created context filter on countries we have chosen country as USA and India Tableau will create a temporary table for this two countries data and if you have any other filers Other filters will be apply on this two countries data
if we don't have any context filter each and individual record will check for all filters
11). what is disadvantage of context filters?
Ans: *The context filter is not frequently changed by the user - if the filter is changed the database must recomputed and rewrite the temporary table, slowing performance.
*When you set a dimension to context, Tableau creates a temporary table that will require a reload each time the view is initiated. For Excel, Access and text data sources, the temporary table created is in an Access table format. For SQL Server, MySQL and Oracle data sources, you must have permission to create a temporary table on your server. For multidimensional data sources, or cubes, temporary tables are not created, and context filters only define which filters are independent and dependent.
12). How To remove the All options from a Tableau auto-filter?
Ans: Right click filter customize uncheck show all option
13). Can we use non-used columns (Columns which are not used in reports but data source has columns) in Tableau Filters?
Ans: Yes!
Ex: In data source I have column like empID, EmpName, EmpDept, EmpDesignation, EmpSalary
In reports I am using empname on columns and empsalry on rows.
I can use empDesignation on Filters
14). what is benefit of tableau extract file over the live connection?
Ans: Extract can be used anywhere without any connection and you can build your own visualizations without connecting to Database.
15). How to combine two excel files with same fields but different data (different years)?
Ans: I have 5 different excel files (2007.xls, 2008.xls.. 2011.xls) with same fields(film name, genre, budget, rating, profitability) but with data from different year(2007 to 2011). Can someone tell me how can I combine the film name, genre and profitability so that I can see the visualization of 2007 to 2011 in a single chart?
Ans: http://community.tableau.com/thread/156217
16). Max no of tables we can join in Tableau?
Ans: We can join max 32 table, it’s not possible to combine more than 32 tables.
17). what is the difference between joining and blending in Tableau?
18). what are Dimensions and Facts?
Ans: Dimensions is nothing but the descriptive text columns and facts are nothing but measures (numerical values).dimension ex: product name city. Facts: Sales, profit
19). Can we place an excel file in a shared location and use it to develop a report and refresh it in regular intervals?
Ans: Yes you can do it.. but for the better performance use extract
20). what is the difference between heat map and tree map?
Ans: A heat map is a great way to compare categories using color and size. In this, you can compare two different measures. Tree map is a very powerful visualization, particularly for illustrating hierarchical (tree-structured) data and part-to-whole relationships.
21). what is the difference between twb and twbx file extensions. Please explain.
Ans: .twb is a live connection, it points to the data source; the user receiving .twb needs permission to said data source and no data is included. .twbx takes data offline, stores the data as a package or zip like file, thereby eradicating the need for permissions from end user; it's now a snapshot in time of the data as of the time it was Saved As .twbx
22). What is dual axis?
Ans: To display two measures in one graph.
Navigation: choose options for any measure -- Choose dual axis.
23). What is blended axis?
Ans: Multiple Measures are shown in single axis and also all the marks shown in single pane
Drag a dimension in a column
Drag the first measure in column
drag 2nd measure in existing axis
http://onlinehelp.tableau.com/current/pro/online/mac/en-us/multiplemeasures_blendedaxes.html
24). what makes Tableau software stands out?
Ans: In my view, Tableau stands out for several reasons:
First, most of the BI tools out there are pricey. However, Tableau has a free offering (Tableau Public) as well as a very popular (also free) academic distribution.
Tableau is well recognized by firms like Forrester research to be one of the most easy to use, and agile products currently available. see here: Tableau Ranks #1 in The Forrester Wave: Advanced Data Visualization (ADV) Platforms That makes it easy to pick up and try new things with, which data visualization people love about it.
On the other hand, unlike some of the other BI tools, Tableau is not a complete technology stack, it is most useful for visualization and analytics. - you will need other products in addition to tableau for heavier enterprise data ETL, maintenance, and storage, etc.
http://www.tableau.com/about/blog/2012/7/tableau-ranks-1-forrester-wave-advanced-data-visualization-adv-platforms-18522
25). How do we do testing in Tableau?
Ans: You can't test in Tableau as far as I know. It is data visualization software.
26). In Dashboard, if we right click on the view, we can able to see delete option and sometimes we can't, what would be the reason?
27). Can you get values from two different sources as a single input into parameter?
Ans: No you cannot. Each data source corresponds to a Tableau workbook. If you include both data variables in the same data source you can input them in the same workbook.
28). How many ways we use parameters in Tableau?
Ans: We can use parameters with filters, calculated fields ,actions, measure-swap, changing views and auto updates
29). What is the use of new Custom SQL Query in tableau?
Ans: Custom SQL Query written after connecting to data for pulling the data in a structured view, One simple example is you have 50 columns in a table, but we need just 10 columns only. So instead of taking 50 columns you can write a sql query. Performance will increase.
30). What are the differences between Tableau Software and Traditional BI tools?
Ans: Tableau provides easy to use, best in class, Visual Analytic capabilities, but it does not help with the plumbing (data foundation). You could, for example, marry SQL Server with Tableau to get the complete package. Tableau licenses are relatively expensive if you are looking to scale.
Traditional BI can handle it all but with significant upfront costs. Higher consulting, hardware and software costs. Among the mega-vendors, only Microsoft can provide a reasonable value proposition. Open source vendors like Pentaho and JasperSoft do not have an abundant enough talent pool, yet.
31). What are the similarities and differences between Tableau software and Palantir?
Ans: Palantir and Tableau are very different; Palantir has its roots in large data computer science problems involving security, payments, fraud detection and the likes; Customers/Investors include Paypal, CIA and others.
Tableau is a visualization player - with roots in Stanford U research; It's Visual Query Language (VizQL) allows users to build visualizations on top of standard data warehouses or spreadsheets.
32). How to create cascading filters without context filter?
Ans: I have filter1 and filter2..Based on filter1 I need to filter2 data
Ex: Filter1 as Country and Filter 2: States
I have chosen country as INDIA and filter2 should display only INDIA states
Choose options of Filter2 states: select option of "Only relevant values”
33). Is Tableau Software good for a strategic acquisition?
Ans: Yes for sure!
It gives you data insight to the extent that others don't.
Helps u plan and point the anomalies and improvise your process for betterment.
34). How to display top 5 and last 5 sales in same view?
Ans: Using filters or calculated fields we can able to display the top 5 and last 5 sales in same view?
35). Design a view to show region wise profit and sales.I did not want line and bar chat should be used for profit and sales. How you will design and please explain?
Ans: Generate the Map using cities -- then Drag the Profit and sales to the Details-- Add the state as Quick filter
36). Design a view in a map such that if user selects any state the cities under that state have to show profit and sales.
Ans: If you want to show the Sales and profit in each and every city under the states in the same work sheet.
According to your question you should have State, City, Sales and Profit filed in your dataset.
1. Double click on the State filed.
2. Drag the City and drop into Marks card (under the State fied)
3. Drag the sales and drop into size.
4. Drag the profit and drop into color.
5. Click on Size legend and increase the size.(75%)
6. Right click on the State field and select show quick filter.
7. Select any state and check whether you got the required view or not.
In this view size indicates the amount of sales and color indicates the Profit values
37). suppose my license expires today, can users able to view the dashboards or workbook which i published in server earlier.
Ans: If your server license expires today, your user name on the server will have the role 'unlicensed' which means you cannot access, but others can. The Site Admin can 'Change Ownership' to another person, so extracts if enabled do not fail.
38). Think that I am using Tableau desktop and have a live connection to Cloud era hadoop data. I need to press F5 to refresh the visualization. Is there any way to automatically refresh the visualization every x minutes instead of pressing F5 every-time?
Ans: Here is the example of refreshing dashboard in every 3 seconds,
Replace api src and server url with yours. The interval below is for 3 seconds.
39). How to add custom Color to Tableau?
Ans: Create Custom Color code in "Preferences.tps"
Navigation: Documents >> My Table Repository>> Preferences.tps
Add custom color code
Note: In tableau 9.0 version we have color picker option..
So problem solved.
40). How can we combine database and flat file data in tableau desktop?
Ans: Connect data two times, one for database tables and one for flat file. The Data>>Edit Relationships
Give a join condition on common column from db tables to flat file
1. Best features of tableau and limitations of tableau.
A. Best visualizations with less it cost,can connect to any database,no plugin required and powerful in memory processing. Limitation : Only supports Windows and Mac.No support to Linux based systems.
2. what are the file size limitations with tableau
A. Officially no limit, but we have observed best peformance with 4GB of data and 278 columns.
3. what is the max file size u used in tableau.
A. 4GB
4. how many max columns we can use in tableau.
A. If you source is Access then 255.
5. what are the limitations of tableau based on size, number of caluclations,
A. No Limitation ,but suggested to work with extracts with max 4 GB.
6. have u ever used tableau to perform etl or any complex caluclations
A. Tableau is a Ajax based Java Scripting data Visualisation tool and it can not peform any ETL actions.Complex calculation : Using Parameter in calculations.
7. have u faced any problems with file size and number of columns which we use in tableau
A. So far no as i have been working with limited data.
8. what is tableau achitecture.
A. It is Client and Server based N-Tier Achitecture. We build Tableau reports in using Tableau Desktop and Deploy them to Tableau Server. Tableau Server runs on 3 diference services Visual Server: This sends the queries to database and then coverts it to the visuals/Images you see in tableau. Database/Repository Server: This manages the connectivity and maintains the data extracts. Application Server: This handles the Authentication and Authorization.
9. what is tableau reader
A. Tableau reader is used to open the .twbx(Tableau packaged Workbook) files and it can only open the files and it can not create new connections and workbooks.
10. What are there any data limitations with tableau public?
A. Tableau Public can connect to Microsoft Excel, Microsoft Access, and multiple text file formats. It has a limit of 1,000,000 rows of data that is allowed in any single file. Yes, your data on Tableau Public is now accessible on the world-wide web and is downloadable by anyone. We strongly suggest you only publish data you are willing to share with anyone.
11. how can u set permissions or protect the data in tableau public?
A. We don't have any options for applying permissions to user in Tableau public. World wide web users will be able to access all files present in tableau public. No Security in public,so don't share any company confidential data.
12. if i delete a workbook from tableau public and there are links to other blogs and other web locations.. what happens to dem?
A. Every thing will be lost. Public is like a repository if you delete any thing in public the links in blogs will show error " File does not exist".
13. did u work on real time reporting on tableau or u worked on back processing?
A. I think question is regarding executing the sql queries from back end or directly executing the queries in tableau desktop.My answer will be: worked on writing the sql queries in sql developer/todd and executing them in tableau desktop.
14. what domain u worked on, when u worked for tableau.
A. My answer will be Insurance domain and currently working on Month end Process.
Hope it helped you..
15. Tableau Dual Axis Chart :
