Pass the Databricks Databricks Certification Databricks-Certified-Professional-Data-Engineer Questions and answers with CertsForce

The events are that a data engineer, User A, has promoted a new pipeline to production by using the REST API to programmatically create several jobs, and a DevOps engineer, User B, has configured an external orchestration tool to trigger job runs through the REST API. Both users authorized the REST API calls using their personal access tokens. The workspace audit logs are logs that record user activities in a Databricks workspace, such as creating, updating, or deleting objects like clusters, jobs, notebooks, or tables. The workspace audit logs also capture the identity of the user who performed each activity, as well as the time and details of the activity. Because these events are managed separately, User A will have their identity associated with the job creation events and User B will have their identity associated with the job run events in the workspace audit logs. Verified References: [Databricks Certified Data Engineer Professional], under “Databricks Workspace” section; Databricks Documentation, under “Workspace audit logs” section.

To deduplicate data against previously processed records as it is inserted into a Delta table, you can use the merge operation with an insert-only clause. This allows you to insert new records that do not match any existing records based on a unique key, while ignoring duplicate records that match existing records. For example, you can use the following syntax:

MERGE INTO target_table USING source_table ON target_table.unique_key = source_table.unique_key WHEN NOT MATCHED THEN INSERT *

This will insert only the records from the source table that have a unique key that is not present in the target table, and skip the records that have a matching key. This way, you can avoid inserting duplicate records into the Delta table.

Delta Lake automatically collects statistics on the first 32 columns of each table. These statistics help optimize query performance through data skipping , which allows Databricks to scan only relevant parts of a table.

This feature significantly improves query efficiency, especially when dealing with large datasets.

Why Other Options Are Incorrect:

Option A: Views do not cache the most recent versions of the source table; they are recomputed when queried.

Option C: Z-ORDER can be applied to any data type, including strings, to optimize read performance.

Option D: Delta Lake does not enforce primary or foreign key constraints.

Exact extract: “Job clusters are created for a job run and terminate when the job completes.”

Databricks recommends addressing disk spilling —which occurs when Spark tasks run out of memory—by increasing memory per core and controlling partition size. Selecting an instance type with a higher memory-to-core ratio (A) provides each task with more available RAM, directly reducing the chance of spilling to disk. Additionally, reducing spark.sql.files.maxPartitionBytes (D) creates smaller partitions, preventing any single task from holding too much data in memory. Increasing partition size (C) or disk capacity (B) does not solve memory bottlenecks, and bandwidth (E) affects network I/O, not spill behavior. Therefore, the correct actions are A and D .

In Databricks Repos, when a user does not have privileges to make changes directly to the main branch of a cloned remote Git repository, the recommended approach is to create a new branch within the Databricks workspace. The developer can then make changes in this new branch, commit those changes, and push the new branch to the remote Git repository. This workflow allows for isolated development without affecting the main branch, enabling the developer to propose changes via a pull request from the new branch to the main branch in the remote repository. This method adheres to common Git collaboration workflows, fostering code review and collaboration while ensuring the integrity of the main branch.

Regex, or regular expressions, are a powerful way of matching patterns in text. They can be used to identify key areas of text when parsing Spark Driver log4j output, such as the log level, the timestamp, the thread name, the class name, the method name, and the message. Regex can be applied in various languages and frameworks, such as Scala, Python, Java, Spark SQL, and Databricks notebooks.  References :

https://docs.databricks.com/notebooks/notebooks-use.html#use-regular-expressions

https://docs.databricks.com/spark/latest/spark-sql/udf-scala.html#using-regular-expressions-in-udfs

https://docs.databricks.com/spark/latest/sparkr/functions/regexp_extract.html

https://docs.databricks.com/spark/latest/sparkr/functions/regexp_replace.html

Exact extract: “window(timeColumn, windowDuration[, slideDuration]) returns a time window for grouping on event-time.”

Exact extract: “If slideDuration is not specified the windows are non-overlapping (tumbling) with length windowDuration.”

Databricks provides different permission levels to control access to clusters. The correct minimal permission required for viewing driver logs is CAN VIEW .

Databricks Cluster Permission Levels:

CAN ATTACH TO:

Allows users to attach notebooks to a cluster but does not allow them to view logs .

Not sufficient for viewing driver logs.

CAN MANAGE:

Grants full control over the cluster, including starting, stopping, and editing configurations.

Too broad for this requirement .

CAN VIEW (Correct Answer):

Allows users to view cluster details, logs, and status but not modify any configurations.

Minimal required permission for viewing logs .

CAN RESTART:

Grants permission to restart the cluster , but does not include log access .

Not sufficient for viewing logs.

Conclusion:

The minimal permission needed to allow the development team to view driver logs is CAN VIEW .