Bronze Questions Flashcards
Why do I need Tableau? What value does Tableau deliver?
Tableau lets your users explore the data and ask questions that lead to business answers and insights that drive the business. Tableau is fast, easy to use, and flexible, allowing all data workers to work independently without the help of report writers or DBAs.
What about performance?
Tableau has no limitations with regards to performance, speed, or size. With Tableau, you can choose to connect directly to your live data or load it into our fast data engine. If you already have a snappy database, tableau will use it for the majority of processing and only bring the results to your desktop. If your data isn’t so fast, business users can load it into our fast data engine and have speed of thought responses.
How hard is it to learn? How long does it take to learn Tableau?
Tableau is designed for the data worker, not just for technical DBAs and report writers. Most of the basic features in Tableau can be learned in an hour or so. Just like with any application, there are many more advanced features that may not be apparent the first time Tableau is used. We have all of our free training and support documents available for free online, so most of our users can be up and running within a matter of hours. New users are supported with both live and on-demand training, support (web, email), Tableau examples and packaged workbooks online, tips and tricks, etc. Also, Tableau has the “Show Me” feature which enables users to select the fields they want to analyze and have Tableau draw the best fit view based on visualization best practices, so this helps people get up and running very quickly.
Who is this for?
Any data worker. Tableau is not tailored toward any vertical or functional area. It’s like asking who can use Excel. Tableau is meant for anyone who needs to explore or ask questions of their data, regardless of technical or analytical background.
We have a BI standard. How is Tableau Different?
Tableau approaches the objectives of BI from a fundamentally different perspective. Instead of having the tools and power centralized in IT, Tableau allows the business professionals to directly interact with their data to answer their questions. This provides freedom for both parties: IT is free to focus on critical tasks and projects without constant interruption from the business users; The business professionals are free to ask any question of the data at any time, or even pursue new data and new questions without the need for deep planning and projects with IT. The end results is a more agile, more responsive business that can make better decisions, faster.
How many visualizations or chart types?
Don’t show ‘Show me’!
Tableau provides an unlimited variety of displays that are a combination of various tools. Users can combine these tools in new ways to arrive at new types of visualizations that best suit their needs. In addition, Tableau provides quick access to many of the most common types of displays including line charts, bar charts, scatter plots, pie charts, area charts, small multiples, Gantt charts, heat maps, highlight tables and cross-tabs. You can even combine together different types of charts to arrive at entirely new visualizations.
I can’t connect to my data, what’s wrong?
What error message are you getting? If it says they need to download the drivers, then kindly suggest they download the drivers. If it is some other error: Our support department can get you set up in no time. Please contact them with your error and they will get back to you shortly (or, for bonus points, create the case in Salesforce for them!)
What databases can you connect to? (be able to list them all)
Best answer – open the connect to data dialog and show them the extensive list. Tableau can connect to file based data such as access and excel as well as relational databases like SQL Server and Oracle and cubes such Essbase and Analysis Services. Tableau can connect to Hadoop through our Cloudera Hadoop Hive connector. For other databases, you can use the ODBC driver. You can also paste data directly into Tableau. Ask them what type of data they have. It makes it easier to say, “oh yes, we connect natively to your environment.”
What is ODBC?
The objective of the ODBC (Open Database Connectivity) standard itself is that it provides a uniform way for products to connect to databases. ODBC drivers are supplied by your database vendor and vary in quality and completeness. Tableau will detect the capabilities of your ODBC driver and match functionality as best we can. When using the ODBC connection, it is often recommended to use it to create Tableau Extracts, rather than running interactive sessions to the data source.
Can I connect to SAP?
Tableau can only connect to the supported databases. If your data is in another format, you must first get it into a supported format by extracting the data or linking to it from another database.
Tableau has been looking into developing support for SAP BW and SAP HANA. However, until this is released, you should continue accessing that data as you do today, which typically means extracting it to Excel.
My excel data doesn’t work with Tableau. What do I do?
KB article written on this topic found here: http://www.tableausoftware.com/community/support/kb/preparing-excel-files-analysis
Remove or exclude introductory and other unnecessary text
Make sure each row contains only one piece of data
Headers: Limit headers to a single row, add missing headers
Missing data: Fill blank cells and delete blank rows
Clean up aggregated and descriptive data
Use Tableau’s Reshaper Plug-in found here: http://www.tableausoftware.com/forum/using-excel-crosstab-data-source
What is the difference between ‘Connect Live’ and importing all or some of my data?
Connecting Live leaves all the data in the source database. Tableau will dynamically query the database to retrieve analytic results. This is great for fast, or rapidly changing databases.
Importing data into the Fast Data Engine optimizes the data, dramatically improving performance when connected to large amounts of data or file based data sets. The extract is static and will need to be refreshed as new data is available, however this can be automated through Tableau Server.
Additionally, you can set up incremental extracts which will only bring in the new data since the last refresh, rather than refreshing the entire extract. For example, you can schedule an incremental extract refresh for every fifteen minutes, and a full refresh during non-peak business hours.
What is the maximum number of rows Tableau can use?
Tableau can connect to unlimited amounts of data. In fact our customers use Tableau as the front end to some of the largest databases in the world – Billions of rows of data. How many rows of data do you have? If you are using a live connection to your giant database, we only retrieve the data needed to answer your question. For example, you have 100 million rows of data and want to find the monthly sales trend for the last 2 years – Tableau only retrieves 24 rows of data. Ok, the daily sales trend for the last 3 years – about 1,000 rows go to Tableau.
If you are using the Fast Data Engine, then you can still effectively use 100’s of millions of rows – even on a laptop with limited memory.
What does ‘architecture aware fast data engine’ mean?
Unlike typical ‘in memory’ databases, Tableau’s fast data engine is not constrained by the amount of RAM on the machine. Tableau only pre-loads the columns used in the analysis and it can even load just part of a column. The ‘architecture aware’ part means that it automatically adapts to the characteristics of your system, even when those characteristics (ie available memory) are dynamic.
Can I join data from 2 different data sources? (be able to demo)
Yes. Make two data connections and add field from each to the worksheet. Tableau calls this Data Blending because it joins the results together rather than forcing you to integrate the detailed data.
Can I connect to multiple databases at once?
Absolutely! You can have each sheet connected to a different type of data and visually combine them in a dashboard.
Or you can combine them in a single sheet using data blending.
Can I augment my data with data I found on a website?
Yes. Select the tabular data that you found on an informative website and paste into a Tableau workbook.
How do cubes differ from relational databases in Tableau?
Cubes Gain: Hierarchical Filters Drill Up/Down per Member Calculated Members (write your own MDX) Default Members Total Using (set the total to use a different calc than the original field) Relational Gain: Robust Calculations – even on dimensions Groups Aggregations (in a cube these are pre-defined) Fast Data Engine Relative Date Filter Row Level Filters