NO.17 Which of the following code blocks returns only rows from DataFrame transactionsDf in which values in column productId are unique?

NO.18 The code block displayed below contains an error. The code block should merge the rows of DataFrames transactionsDfMonday and transactionsDfTuesday into a new DataFrame, matching column names and inserting null values where column names do not appear in both DataFrames. Find the error.
Sample of DataFrame transactionsDfMonday:
1.+————-+———+—–+——-+———+—-+
2.|transactionId|predError|value|storeId|productId| f|
3.+————-+———+—–+——-+———+—-+
4.| 5| null| null| null| 2|null|
5.| 6| 3| 2| 25| 2|null|
6.+————-+———+—–+——-+———+—-+
Sample of DataFrame transactionsDfTuesday:
1.+——-+————-+———+—–+
2.|storeId|transactionId|productId|value|
3.+——-+————-+———+—–+
4.| 25| 1| 1| 4|
5.| 2| 2| 2| 7|
6.| 3| 4| 2| null|
7.| null| 5| 2| null|
8.+——-+————-+———+—–+
Code block:
sc.union([transactionsDfMonday, transactionsDfTuesday])

NO.19 Which of the following code blocks performs a join in which the small DataFrame transactionsDf is sent to all executors where it is joined with DataFrame itemsDf on columns storeId and itemId, respectively?

NO.20 Which of the following describes slots?

NO.21 Which of the following statements about executors is correct, assuming that one can consider each of the JVMs working as executors as a pool of task execution slots?

NO.22 Which of the following code blocks shuffles DataFrame transactionsDf, which has 8 partitions, so that it has
10 partitions?

NO.23 Which of the following code blocks returns a one-column DataFrame for which every row contains an array of all integer numbers from 0 up to and including the number given in column predError of DataFrame transactionsDf, and null if predError is null?
Sample of DataFrame transactionsDf:
1.+————-+———+—–+——-+———+—-+
2.|transactionId|predError|value|storeId|productId| f|
3.+————-+———+—–+——-+———+—-+
4.| 1| 3| 4| 25| 1|null|
5.| 2| 6| 7| 2| 2|null|
6.| 3| 3| null| 25| 3|null|
7.| 4| null| null| 3| 2|null|
8.| 5| null| null| null| 2|null|
9.| 6| 3| 2| 25| 2|null|
10.+————-+———+—–+——-+———+—-+

NO.24 The code block displayed below contains an error. The code block should configure Spark so that DataFrames up to a size of 20 MB will be broadcast to all worker nodes when performing a join.
Find the error.
Code block:

NO.25 The code block displayed below contains an error. The code block should write DataFrame transactionsDf as a parquet file to location filePath after partitioning it on column storeId. Find the error.
Code block:
transactionsDf.write.partitionOn(“storeId”).parquet(filePath)

NO.26 Which of the following code blocks stores DataFrame itemsDf in executor memory and, if insufficient memory is available, serializes it and saves it to disk?

NO.27 Which of the following is the deepest level in Spark’s execution hierarchy?

NO.28 Which of the following are valid execution modes?

NO.29 Which of the following describes a difference between Spark’s cluster and client execution modes?

NO.30 The code block shown below should return a one-column DataFrame where the column storeId is converted to string type. Choose the answer that correctly fills the blanks in the code block to accomplish this.
transactionsDf.__1__(__2__.__3__(__4__))

NO.31 The code block shown below should read all files with the file ending .png in directory path into Spark.
Choose the answer that correctly fills the blanks in the code block to accomplish this.
spark.__1__.__2__(__3__).option(__4__, “*.png”).__5__(path)

NO.32 Which of the following code blocks stores a part of the data in DataFrame itemsDf on executors?