Practice Question Answers and Explanations

1. Correct answers: B, C

   You find measures in analytic views, calculation views of type cube with star join (the new type of analytic view), and calculation views of type cube. Attribute views do not contain measures—only attributes!

2. Correct answer: B

   False. A database view does not store data in the database.

3. Correct answers: B, C

   A traditional cube is represented by an analytic view or a calculation view of type cube with star join. Both are different from a cube in that they do not store any data like a cube does. An attribute view and a calculation view of type dimension are similar to a dimension table.

4. Correct answer: A

   A referential join gives the same results as an inner join but speeds up the calculations in some cases by assuming referential integrity of the data. It is the optimal join type in SAP HANA.

5. Correct answer: C

   A temporal join requires FROM and TO fields in the table on the right side of the join and a date-time column in the table on the left side of the join.

6. Correct answer: A

   We cannot “measure” or perform calculations on the color green. Green is not a spatial data type. CDS views are not relevant in this context.

7. Correct answer: B

   False. A view does NOT always show all the available columns of the underlying tables. You have to select the output fields of a view. The word always in the statement is what makes it false.

8. Correct answer: C

   A right outer join is the inverse of the left outer join. Therefore, if you reverse the order of the tables, you can “reverse” the join type. It is important to note that this does not work for a text join. A text join is only equivalent to a left outer join. For a text join, you have to be careful about the order of the tables.

9. Correct answer: B

   The data displayed in the data foundation of an SAP HANA information view is called measures. In SAP HANA, we talk about attributes and measures. The other names might be used in other data modeling environments, but not in SAP HANA.

10. Correct answer: C

    The player information is used as master data, and the scores are used as transactional data. You cannot perform calculations on the players. Therefore, this data is used in the dimensions and is seen as master data. You definitely perform calculations on the scores, so these are used in the fact tables, which means they are transactional data.

11. Correct answer: B

    Figure 4.17 shows the SPRAS column and shows a list of languages. The need for a translation is also hinted at in the question, meaning this should be a text join. There is not enough information to select any of the other answer options.

12. Correct answers: B, C

    You should use CDS to create a schema because the database administrator should not get those privileges in the production system and the focus should be on the business requirements.

13. Correct answer: C

    Look carefully at Figure 4.18. The question asks you to find all the customers that received quotes but did NOT receive invoices.

    The answer only gives us left outer or right outer as options. Because the question states they want all customers from the quotes tables, you might try a left outer join first.

    Now look at Figure 4.3 to see the difference between the left and right outer joins. Look especially at the where the NULL values are shown. With a left outer join, the NULL values are found in the right table. With a right outer join, the NULL values are found in the left table.

    We want to find the customers that did not get invoices. With a left outer join, the NULL values are found on the right side: That group is the one we are looking for. Therefore, filter for the NULL values on the right table.

    [»] Note

    Any time that a negative phrase or word is used in the certification exam, it is shown in capital letters to bring attention to the fact that it is a negative word.

14. Correct answer: A

    True. Yes, the depth of your hierarchy levels can vary when you use a parent–child hierarchy.

15. Correct answer: C

    You should use a referential join.

    There are two distractors to try and throw you off track:

    • A temporal join uses FROM and TO fields, but only for date-time fields. This example is for airports.
    • The second distractor was to try to get you to select the text join: The language code has nothing to do with translations, but has to do with the airline’s primary language.

    Choose a referential join because you can see the same people traveling in both tables, so it seems that these two tables have referential integrity.

    If the tables did not have referential integrity, you would have chosen an inner join.

16. Correct answer: D

    A spatial join can give the distance between different points on a map.

    There are two ways you can find the largest distance between any two clinics:

    • Use a ranking to find the top 10 values.
    • Use an aggregation with the maximum option.
17. Correct answer: B

    See the full solution in Figure 4.22.

    X = Customer 1, Y = 400, Z = 400.

    Note that we are using average in the aggregation node, not sum.

    In the ranking node, we are asking for the bottom 10, not the top 10.

    

    Figure 4.22 Full Solution: X = Customer 1, Y = 400, Z = 400

18. Correct answer: D

    You expect to use a self-join when you build a parent–child hierarchy. See Figure 4.16 for an illustration.

19. Correct answer: B

    To see everything on the right table, use a right outer join.

    Note that these tables do not have referential integrity. If we had asked the question a little differently, this could have been important.