QUESTION: 73

True or False: A LEFT JOIN or INNER JOIN creates a row each time the join criteria is satisfied, which can result in duplicate rows. One way to avoid this is to use data blending instead.

True
False

Answer(s): A

Explanation:

Joins combine tables by adding more columns of data across similar row structures. This can cause data loss or duplication if tables are at different levels of detail, and joined data sources must be fixed before analysis can begin.

Inner join

Left Join

Blends, unlike relationships or joins, never truly combine the data. Instead, blends query each data source independently, the results are aggregated to the appropriate level, then the results are presented visually together in the view.

Reference:

https://help.tableau.com/current/pro/desktop/en-us/multiple_connections.htm

Reveal Solution Next Question

QUESTION: 74

______________is a technique in Tableau which will identify marks with similar characteristics

Clustering
Grouping
Sets
Union

Answer(s): A

Explanation:

Cluster analysis partitions marks in the view into clusters, where the marks within each cluster are more similar to one another than they are to marks in other clusters.

Reference:

https://help.tableau.com/current/pro/desktop/en-us/clustering.htm

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QUESTION: 75

Which of the following is the correct way to calculate Profit Ratio in Tableau?

Profit / Sales
Sales / Profit
SUM(Profit) / SUM(Sales)
SUM(Sales)/SUM(Profit)

Answer(s): C

Explanation:

THIS IS A VERY IMPORTANT QUESTION
Aggregation is an important concept to consider when creating calculated fields. A calculated field for SUM([Profit]) / SUM([Sales]) will give you a very different answer than [Profit] / [Sales], even though both formulas are valid.
If you do not provide the aggregation within the calculated field, Tableau will calculate the equation for every record ( row ) in your analysis, then aggregate the answers for all of the rows together when the calculated field is added to the view.
In simple terms, if specify the aggregation such as SUM, what Tableau will do is that it will first calculate the sum of the Profit column ( say x ), then calculate the sum of the Sales column ( say y ), and then simply apply x/y ---> This is what we expect! Perfect!

BUT, if you don't specify the aggregation, it will go to every single ROW, perform Profit / Sales, and then aggregate the answers calculated for each row. This is simply NOT what we wan't!

An example: