Demo Databricks Databricks-Certified-Professional-Data-Engineer Exam Questions
Demo practice questions for guest users.
Question 1
An upstream system has been configured to pass the date for a given batch of data to the Databricks
Jobs API as a parameter. The notebook to be scheduled will use this parameter to load data with the
following code:
df = spark.read.format("parquet").load(f"/mnt/source/(date)")
Which code block should be used to create the date Python variable used in the above code block?
Correct Answer: E
Explanation:
The code block that should be used to create the date Python variable used in the above code block
The code block that should be used to create the date Python variable used in the above code block
is:
dbutils.widgets.text(“date”, “null”) date = dbutils.widgets.get(“date”)
This code block uses the dbutils.widgets API to create and get a text widget named “date” that can
accept a string value as a parameter1. The default value of the widget is “null”, which means that if
no parameter is passed, the date variable will be “null”. However, if a parameter is passed through
the Databricks Jobs API, the date variable will be assigned the value of the parameter. For example, if
the parameter is “2021-11-01”, the date variable will be “2021-11-01”. This way, the notebook can
use the date variable to load data from the specified path.
The other options are not correct, because:
Option A is incorrect because spark.conf.get(“date”) is not a valid way to get a parameter passed
through the Databricks Jobs API. The spark.conf API is used to get or set Spark configuration
properties, not notebook parameters2.
Option B is incorrect because input() is not a valid way to get a parameter passed through the
Databricks Jobs API. The input() function is used to get user input from the standard input stream,
not from the API request3.
Option C is incorrect because sys.argv1 is not a valid way to get a parameter passed through the
Databricks Jobs API. The sys.argv list is used to get the command-line arguments passed to a Python
script, not to a notebook4.
Option D is incorrect because dbutils.notebooks.getParam(“date”) is not a valid way to get a
parameter passed through the Databricks Jobs API. The dbutils.notebooks API is used to get or set
notebook parameters when running a notebook as a job or as a subnotebook, not when passing
parameters through the API5.
Reference: Widgets, Spark Configuration, input(), sys.argv, Notebooks
Question 2
The Databricks workspace administrator has configured interactive clusters for each of the data
engineering groups. To control costs, clusters are set to terminate after 30 minutes of inactivity. Each
user should be able to execute workloads against their assigned clusters at any time of the day.
Assuming users have been added to a workspace but not granted any permissions, which of the
following describes the minimal permissions a user would need to start and attach to an already
configured cluster.
Correct Answer: D
Explanation:
https://learn.microsoft.com/en-us/azure/databricks/security/auth-authz/access-control/cluster-acl https://docs.databricks.com/en/security/auth-authz/access-control/cluster-acl.html
Question 3
When scheduling Structured Streaming jobs for production, which configuration automatically recovers from query failures and keeps costs low?
Correct Answer: D
Explanation:
The configuration that automatically recovers from query failures and keeps costs low is to use a new
The configuration that automatically recovers from query failures and keeps costs low is to use a new
job cluster, set retries to unlimited, and set maximum concurrent runs to 1. This configuration has
the following advantages:
A new job cluster is a cluster that is created and terminated for each job run. This means that the
cluster resources are only used when the job is running, and no idle costs are incurred. This also
ensures that the cluster is always in a clean state and has the latest configuration and libraries for the
job1.
Setting retries to unlimited means that the job will automatically restart the query in case of any
failure, such as network issues, node failures, or transient errors. This improves the reliability and
availability of the streaming job, and avoids data loss or inconsistency2.
Setting maximum concurrent runs to 1 means that only one instance of the job can run at a time. This
prevents multiple queries from competing for the same resources or writing to the same output
location, which can cause performance degradation or data corruption3.
Therefore, this configuration is the best practice for scheduling Structured Streaming jobs for
production, as it ensures that the job is resilient, efficient, and consistent.
Reference: Job clusters, Job retries, Maximum concurrent runs
Question 4
The data engineering team has configured a Databricks SQL query and alert to monitor the values in
a Delta Lake table. The recent_sensor_recordings table contains an identifying sensor_id alongside
the timestamp and temperature for the most recent 5 minutes of recordings.
The below query is used to create the alert:
The query is set to refresh each minute and always completes in less than 10 seconds. The alert is set
to trigger when mean (temperature) > 120. Notifications are triggered to be sent at most every 1
minute.
If this alert raises notifications for 3 consecutive minutes and then stops, which statement must be
true?
Correct Answer: E
Explanation:
This is the correct answer because the query is using a GROUP BY clause on the sensor_id column, which means it will calculate the mean temperature for each sensor separately. The alert will trigger when the mean temperature for any sensor is greater than 120, which means at least one sensor had an average temperature above 120 for three consecutive minutes. The alert will stop when the mean temperature for all sensors drops below 120. Verified Reference: [Databricks Certified Data Engineer Professional], under “SQL Analytics” section; Databricks Documentation, under “Alerts” section.
Question 5
A junior developer complains that the code in their notebook isn't producing the correct results in
the development environment. A shared screenshot reveals that while they're using a notebook
versioned with Databricks Repos, they're using a personal branch that contains old logic. The desired
branch named dev-2.3.9 is not available from the branch selection dropdown.
Which approach will allow this developer to review the current logic for this notebook?
Correct Answer: B
Explanation: