Midterm 2

Question 1

True/False: In Spark, an action triggers the execution of the computation that has been defined by transformations.

Answer 1

True

Question 2

Lineage tracking in Spark is essential for:

Answer 2

Recovering lost data partitions.

Question 3

True/False: Columnar storage can significantly reduce the amount of data read from disk for queries accessing a subset of columns.

Answer 3

True

Question 4

How does column format benefit big data analytics compared to row format?

Answer 4

By avoiding unnecessary attribute reading from disk.

Question 5

True/False: Columnar formats can apply more efficient compression techniques because of the uniformity of data within each column.

Answer 5

True

Question 6

Which application scenario is more suitable for MongoDB than Parquet?

Answer 6

Managing real-time user interactions and profiles on a social networking site.

Question 7

Which application scenario is more suitable for MongoDB than Parquet?

Answer 7

Tracking and updating inventory levels in real-time across global warehouses for an international logistics company.

Question 8

Consider the following records in a MongoDB collection:

Record 1: { “name”: “Alice”, “numbers”: [3, 5, 8] }

Record 2: { “name”: “Bob”, “numbers”: [2, 4] }

Record 3: { “name”: “Charlie”, “numbers”: [5, 2, 3] }

Record 4: { “name”: “Dana”, “numbers”: [1, 9] }]
Which record would appear first in a MongoDB collection sorted in descending order of the numbers field?

Answer 8

Record 4