Maersk - NoSQL


 NoSQL

1.   Consider a relation book (tittle, price) which contains the titles and prices of different books. Assuming that no two books have the same price, what does the following SQL query list?

Select title from book as B

Where (select count (*)

From book as T

Where T.price > B.price) < 7

o  Titles of the six most expensive books.

o  Titles of the seven most expensive books.

o  Titles of the seventh expensive books.

o  Titles of the sixth expensive books.

2.   What would be the asymptotic time complexity to inseryt an element at the second position in the linked list?

o  O(1)

o  O(n3)

o  O(n2)

o  O(n)

3.   Most NoSQL databases support automatic __________ meaning that you get high availability and disaster record.

o  Scalability

o  Processing

o  Replication

o  All of the mentioned options

4.   Consider the following three SQL queries (Assume the data in the people table):

a)   Select Name from people where Age>21;

b)  Select Name from people where Height>180;

c)   Select Name from people where (Age>21) or (Height>180);

If the SQL queries a) and b) above, return 10 rows and 7 rows in the result set respectively, then what is one possible number of rows returned by the SQL query c)?

o  7

o  10

o  3

o  21

5.   Which of the statement is true about temporary space?

o  Temporary space is subtracted from Sysadmin

o  Temporary space is spool space currently not used.

o  Temporary space is permanent space currently not used

o  Temporary space is assigned at the table level

6.   From the following statements which of them is/are true about SQL

1)   All attributes used in the group by clause must appear in the select clause

2)  An SQL query can contain a having clause only if it has a group by clause

3)  An SQL query can contain a having clause even if it does not have a group by clause

4)  Not all attributes used in the group by clause need to appear in the select clause

o  1 and 2

o  All of the mentioned options

o  3 and 4

o  1, 3 and 4

7.   Which of the following is not a set operation?

o  Intersection

o  Set difference

o  And operation

o  Union

8.   Which of the following is a wide-column store?

o  MongoDB

o  Cassandra

o  Riak

o  Redis

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