Databricks Databricks-Certified-Professional-Data-Engineer 問題集

質問 1：
What is the first of a Databricks Python notebook when viewed in a text editor?
A. //Databricks notebook source
B. % Databricks notebook source
C. %python
D. -- Databricks notebook source
正解：B
解説: (Topexam メンバーにのみ表示されます)

質問 2：
Two of the most common data locations on Databricks are the DBFS root storage and external object storage mounted with dbutils.fs.mount().
Which of the following statements is correct?
A. Neither the DBFS root nor mounted storage can be accessed when using %sh in a Databricks notebook.
B. By default, both the DBFS root and mounted data sources are only accessible to workspace administrators.
C. DBFS is a file system protocol that allows users to interact with files stored in object storage using syntax and guarantees similar to Unix file systems.
D. The DBFS root is the most secure location to store data, because mounted storage volumes must have full public read and write permissions.
E. The DBFS root stores files in ephemeral block volumes attached to the driver, while mounted directories will always persist saved data to external storage between sessions.
正解：C
解説: (Topexam メンバーにのみ表示されます)

質問 3：
A data engineer is testing a collection of mathematical functions, one of which calculates the area under a curve as described by another function.
Which kind of the test does the above line exemplify?
A. Manual
B. functional
C. Integration
D. Unit
正解：D
解説: (Topexam メンバーにのみ表示されます)

質問 4：
Which statement describes Delta Lake optimized writes?
A. Optimized writes logical partitions instead of directory partitions partition boundaries are only represented in metadata fewer small files are written.
B. Before a job cluster terminates, OPTIMIZE is executed on all tables modified during the most recent job.
C. An asynchronous job runs after the write completes to detect if files could be further compacted; yes, an OPTIMIZE job is executed toward a default of 1 GB.
D. A shuffle occurs prior to writing to try to group data together resulting in fewer files instead of each executor writing multiple files based on directory partitions.
正解：D
解説: (Topexam メンバーにのみ表示されます)

質問 5：
Which statement describes Delta Lake Auto Compaction?
A. Before a Jobs cluster terminates, optimize is executed on all tables modified during the most recent job.
B. An asynchronous job runs after the write completes to detect if files could be further compacted; if yes, an optimize job is executed toward a default of 1 GB.
C. An asynchronous job runs after the write completes to detect if files could be further compacted; if yes, an optimize job is executed toward a default of 128 MB.
D. Optimized writes use logical partitions instead of directory partitions; because partition boundaries are only represented in metadata, fewer small files are written.
E. Data is queued in a messaging bus instead of committing data directly to memory; all data is committed from the messaging bus in one batch once the job is complete.
正解：C
解説: (Topexam メンバーにのみ表示されます)

質問 6：
The data engineer is using Spark's MEMORY_ONLY storage level.
Which indicators should the data engineer look for in the spark UI's Storage tab to signal that a cached table is not performing optimally?
A. The RDD Block Name included the '' annotation signaling failure to cache
B. Size on Disk is> 0
C. On Heap Memory Usage is within 75% of off Heap Memory usage
D. The number of Cached Partitions> the number of Spark Partitions
正解：A
解説: (Topexam メンバーにのみ表示されます)