Databricks Certified Data Engineer Professional Dumps & Exam Prep Guide

Prepare for the Databricks Certified Data Engineer Professional exam with these latest dumps and practice questions. Tailored for advanced data engineers, this resource covers in-depth topics like advanced Spark optimization, structured streaming, Delta Live Tables (DLT), Databricks SQL, and MLOps on the Lakehouse platform. Each dump and practice test reflects the exam's real difficulty level, helping you identify knowledge gaps and boost confidence. Whether you're looking for free Databricks professional dumps or simulated test scenarios, these materials provide comprehensive, hands-on readiness for your certification. Ideal for seasoned data professionals aiming to validate their elite skills with Databricks technologies.

Databricks Certified Data Engineer Professional Dumps & Sample Questions List :

1. You need to create a deep clone of a Delta table that is currently stored on an external storage location. Which of the following conditions must be met for the deep clone operation to succeed?

1. The deep clone process requires you to manually copy data files before executing the clone operation.

2. The deep clone operation does not require any additional permissions beyond metadata access.

3. The storage account must allow read and write permissions for the source and target locations.

4. The source table must not have any active readers.

2. You are tasked with writing a large PySpark DataFrame to disk in parquet format, but you need to manually control the size of the part-files to optimize the read performance in a downstream ETL process. Which combination of actions should you take to control the size of the individual part-files when saving the DataFrame? (Select two)

1. Configure the spark.sql.files.maxPartitionBytes to set the maximum file size for part-files generated.

2. Use the coalesce(n) method before writing the DataFrame, where n is the desired number of output files.

3. Use the repartition(n) method before writing the DataFrame, where n is based on the size of the part-files you want to generate.

4. Manually calculate the DataFrame size and write the DataFrame using a custom file writer to manage file size.

5. Enable the spark.sql.files.maxRecordsPerFile configuration, setting it to limit the number of records per part-file.

3. You are implementing a streaming pipeline in Databricks to ingest log data from IoT devices into the bronze layer of your Delta Lake. The data arrives continuously with some malformed records, missing fields, and out-of-range values. You need to promote the data to the silver layer to ensure that it can be used in real-time monitoring dashboards. Which transformation step is the most critical when promoting the streaming IoT data from the bronze layer to the silver layer in this scenario?

1. Time Travel Querying: Implementing time travel features to track changes to the dataset over time and query the dataset as it existed at any specific point.

2. Schema Enforcement: Enforcing strict schema validation rules to reject any data that does not conform to the expected structure or data types, while preserving valid data.

3. Outlier Detection: Identifying and removing data points that fall outside of the expected range for sensor readings in the IoT data.

4. Upsert (MERGE INTO): Merging incoming streaming records into an existing dataset in the silver layer based on a unique device ID.

4. You are designing a production streaming system that processes real-time financial transactions. The system must meet stringent cost and latency SLAs, with sub-second latency requirements and a maximum cloud infrastructure budget. Which of the following techniques would be most effective for optimizing the system to meet both cost and latency SLAs?

1. Apply Trigger.Once to minimize cluster resource usage by processing batches only when new data arrives.

2. Reduce the number of shuffle operations by optimizing the data partitioning to minimize network overhead during processing.

3. Use a large cluster size with many small executors to reduce task overhead and achieve lower latency.

4. Enable high checkpoint frequency to reduce the risk of data loss, even if it leads to increased I/O operations.

5. Leverage auto-scaling for the cluster, adjusting the number of nodes based on workload demand to balance cost and performance.

5. You have a Databricks notebook that performs real-time streaming ETL using Structured Streaming and Delta Lake. Recently, there have been intermittent failures, and the job is automatically retrying but is still failing after a few attempts. To monitor and troubleshoot these failures, which logging technique would best capture detailed error information about what went wrong?

1. Add cloud-native logging (e.g., AWS CloudWatch, Azure Monitor) to log all Databricks errors across the cluster.

2. Turn on Spark Event Logs to capture detailed information about the transformations and actions in the job.

3. Use the Delta Lake Logs to capture streaming-specific logs and checkpoints related to job execution.

4. Enable Audit Logs to track who ran the job and what operations were performed.

5. Enable Structured Streaming Progress Logs to capture the state of the streaming queries and any errors during each micro-batch.

6. You are designing a customer dimension table to track customer information such as name, email, and address. The business requires that only the most recent information for each customer be retained in the table, with no history of previous changes. You need to implement this as a Slowly Changing Dimension (SCD) Type 1 table in Delta Lake. Which of the following is the correct approach to implement this in Delta Lake?

1. Use Delta Lake's MERGE INTO operation to overwrite existing records with new data for each customer.

2. Use Delta Lake's UPDATE statement to modify only specific fields that have changed, leaving other fields untouched.

3. Partition the Delta Lake table by the customer ID and apply UPSERT operations to each partition, retaining historical data.

4. Implement a Delta Lake table with a versioned column to track changes but only expose the latest version of each record.

7. You are tasked with creating a cloned version of a Delta Lake table to test modifications on data without affecting the source table. Given the following table structure:

• The source Delta table stores transactional data with millions of records and daily updates.

• You need to create a clone for experimenting with schema changes and validate transformations.

Which of the following actions should be considered when choosing between a shallow or deep clone? (Select two)

1. Shallow clone creates a full copy of the data, which can significantly increase storage usage.

2. Shallow clone creates a reference to the source table's data files and metadata without copying the actual data.

3. Deep clone is more efficient for quickly experimenting with schema changes since it avoids copying the data files.

4. Deep clone copies both data and metadata from the source table, creating a completely independent copy of the table.

5. Changes to the shallow clone are reflected back in the source table, which can disrupt production data integrity.

8. A data engineer is working with a Databricks notebook and needs to install a Python package from PyPI. They want to ensure that the package is installed on all worker nodes in the cluster, but only for the duration of their notebook session. Which of the following methods would achieve this?

1. Add the package to the cluster libraries in the Databricks UI

2. Use %conda install in a notebook cell

3. Use dbutils.library.install in a notebook cell to install the package

4. Use %sh pip install in a notebook cell

5. Use %pip install in a notebook cell

9. A data engineer is tasked with ensuring that all Delta Lake tables are created as external, unmanaged tables in a Lakehouse environment. What is the correct approach to guarantee that a table is external and unmanaged?

1. Specify the DELTA_TABLE_TYPE as UNMANAGED in the Delta Lake configuration.

2. Set the AUTO_MANAGE flag to OFF in the workspace settings.

3. Use the LOCATION keyword when creating the table to specify the external storage path.

4. Set the EXTERNAL_TABLE parameter to TRUE in the table creation statement.

5. Add a CLEANUP_POLICY to disable automatic management for Delta tables.

10. You are working with a Delta Lake table that tracks product inventory. Due to frequent updates and deletions in the dataset, you decide to use Change Data Feed (CDF) to simplify downstream consumption of these changes by other systems. What is the primary advantage of using CDF in this scenario compared to traditional methods for tracking and propagating changes?

1. CDF enables users to partition tables automatically based on changed data to optimize incremental loads

2. CDF automatically propagates all changes to external systems without requiring manual intervention

3. CDF creates new versions of the entire dataset, which optimizes query performance for read-heavy operations

4. CDF provides an efficient way to identify only the rows that have been inserted, updated, or deleted since the last time data was read.

11. You are working in a shared Delta Lake environment, where multiple users are running concurrent jobs to read and update a large Delta table. Which of the following scenarios could lead to a conflict when using Delta Lake's Optimistic Concurrency Control? (Select two)

1. Two concurrent append operations that add new rows to the Delta table.

2. A write operation on a Delta table with a static schema and a concurrent schema evolution operation.

3. Two concurrent write operations attempt to modify the same rows in the Delta table.

4. A read operation and a concurrent write operation occur on the same table.

5. Two concurrent write operations attempt to modify different partitions of the Delta table.

12. You are tasked with designing a data model for a retail system. The system includes tables that store information about orders, products, and customers. You want to use a normalized model to reduce data redundancy and ensure data integrity. To enhance query performance, you decide to implement lookup tables for product categories and customer regions. However, some queries will involve joining these lookup tables with large fact tables. Which approach should you take to implement the lookup tables while minimizing performance issues in a normalized model?

1. Denormalize the lookup tables by embedding them into the fact tables to avoid joins during query execution.

2. Use broadcast joins with lookup tables to minimize the performance impact of joining them with large fact tables during query execution.

3. Normalize the data model by creating separate lookup tables for product categories and customer regions and use join operations in queries to maintain data integrity.

4. Partition the fact tables based on product category and customer region to optimize performance when querying against the lookup tables.

13. You are working with a large PySpark DataFrame consisting of over 100 million rows of customer transaction data. To optimize storage and future read performance, you need to write this DataFrame to disk in a highly efficient format (e.g., Parquet) while ensuring each part-file is approximately 1GB in size. Your cluster consists of 10 nodes, and you want to balance file size with the number of output files to avoid creating too many small files. Which of the following approaches will best allow you to manually control the size of the output files when writing the DataFrame to disk?

1. Use the .coalesce() method to reduce the number of partitions based on your desired file size, and then write the DataFrame to disk.

2. Use the .write() method with the maxRecordsPerFile option set to control the size of individual part-files based on the number of rows.

3. Use the .repartitionByRange() method to partition the data based on a specific column range, ensuring evenly sized part-files.

4. Use the .repartition() method to set the number of partitions to match the desired part-file count, and then write the DataFrame directly to disk.

14. A data engineering team needs to adjust permission settings on a Databricks Job after realizing that the current owner has left the organization. They need to transfer ownership to another individual in the team but are unclear about how to properly configure Databricks Jobs permissions. Which statement is accurate regarding how ownership and permissions work for Databricks Jobs?

1. Transferring ownership of a Databricks Job is only allowed between individual users, not groups or service principals.

2. Once a user creates a Databricks Job, they retain exclusive "Owner" privileges, and no other users can be assigned these privileges.

3. Groups cannot be granted any privileges for a Databricks Job, even if a workspace administrator attempts to assign permissions.

4. A Databricks Job can have multiple owners, but only workspace administrators can assign additional owners.

5. A user can transfer ownership of a Databricks Job to any other user, provided they have "Manage" or higher-level privileges.

15. A data engineer needs to install a specific Python library for data processing that is not pre-installed in the Databricks environment. They want to ensure that the library is available to all the nodes in the cluster during their session but scoped only to their notebook. What is the correct method to achieve this?

1. Use the Databricks Libraries UI to manually upload the package to the cluster.

2. Modify the cluster's init script to include the pip install command.

3. Install the package globally using !pip install in a notebook cell.

4. Use %pip install in a notebook cell to install the package on all nodes in the currently active cluster.

5. Run pip install directly in the terminal using the %sh magic command.

16. Your company’s data lakehouse is built on Delta Lake, and you are tasked with implementing a solution that allows for incremental processing of data, including propagating delete operations from the source system. You’ve decided to use Change Data Feed (CDF) to track changes, including deletes. However, you also want to ensure that delete operations do not impact queries on historical data. What is the best approach to efficiently handle and propagate these deletes while keeping the historical data intact?

1. Use CDF to identify the deleted records and delete them from the Delta table

2. Ignore CDF and run full table scans to identify and remove deleted records periodically

3. Use CDF to mark records as deleted with a custom flag, then remove them during cleanup

4. Use CDF to identify deleted records and filter them during queries, but retain them in the table

17. You are designing a data model in Databricks for a retail company that stores customer transactions. The company wants to analyze transactions on a daily and monthly basis, considering the possibility of data skew due to uneven distribution of sales in different regions. Which partitioning strategy would you choose to optimize the performance of queries that focus on date-based aggregations and why?

1. Partition by region and product_id.

2. Partition by year and month.

3. Partition by day.

4. Partition by date and region.

18. You are working with a large dataset of customer transactions stored in a Delta Lake table. The data is partitioned by the region column. You notice that during batch processing, one partition (region = 'East') has significantly more data than other partitions, causing skew in the distribution of tasks across executors. You want to optimize the distribution without increasing the number of partitions drastically. Which of the following techniques should you use?

1. repartition(4)

2. coalesce(4)

3. coalesce(1)

4. rebalance()

19. You are implementing an incremental processing pipeline for a retail company that processes customer transaction data. The data includes a transaction_id, customer_id, store_id, and transaction_date. You need to partition the data for optimal performance, ensuring that queries on recent transactions are fast and the pipeline can scale as the data grows. Which of the following partitioning strategies is the most effective for this use case?

1. Partition the data by store_id to allow queries to filter by specific stores, improving performance for store-level analysis.

2. Partition the data by transaction_date to minimize the amount of data scanned for queries that analyze recent transactions and for incremental processing.

3. Partition the data by transaction_date and customer_id to ensure optimal distribution and query performance for both time-based and customer-based queries.

4. Partition the data by transaction_id to ensure even distribution of data across partitions and to make querying individual transactions faster.

20. You have run a Spark job that performs a large-scale join operation between two datasets. The job completes, but the performance is significantly slower than expected. You navigate to the Spark UI to investigate potential bottlenecks. Which of the following sections of the Spark UI would best help you understand the stage execution time and identify skew in task distribution?

1. Storage Tab

2. SQL Tab

3. Executors Tab

4. Stages Tab

5. Jobs Tab

21. You are tasked with cloning a job in Databricks using the REST API. The job you want to clone has the ID 1234. You also need to modify the cloned job's name to Cloned Job. Which of the following REST API calls correctly clones the job and updates the name of the cloned job?

1. POST /api/2.1/jobs/clone with a request body that includes "job_id": 1234 and "new_settings": {"name": "Cloned Job"}

2. POST /api/2.1/jobs/copy with a request body that includes "job_id": 1234 and "name": "Cloned Job"

3. POST /api/2.1/jobs/create with a request body that includes "job_id": 1234 and "new_name": "Cloned Job"

4. POST /api/2.1/jobs/clone with a request body that includes "job_id": 1234 and "job_name": "Cloned Job"

22. You are a data engineer at a retail company managing a large dataset of transaction records stored in Delta Lake. The dataset is partitioned by year, month, and day. The company requires that all transaction data older than two years be archived to a secondary storage location, and data older than five years must be deleted permanently. The dataset is continuously growing, and the data is accessed both for reporting (batch queries) and for periodic audits (incremental queries). To meet these requirements, you need to design an efficient solution for archiving and deleting old data while minimizing the impact on query performance. Which of the following approaches best meets the company's requirements for archiving and deleting old data?

1. Run a simple DELETE operation on the Delta table for records older than five years, then use Delta Lake’s VACUUM to remove the files from disk.

2. Coalesce the partitions by day to reduce the total number of small files, improving the query performance for batch jobs, and then archive and delete data using the Delta Lake OPTIMIZE command.

3. Repartition the Delta table by year and month to make it easier to archive data older than two years and delete data older than five years by removing entire partitions.

4. Use Delta Lake’s Time Travel feature to query the table for transactions older than five years, archive them to a secondary location, and then run DELETE for these records followed by VACUUM to remove them permanently.

23. You are working on a large dataset stored in Delta Lake and notice that your Spark jobs are experiencing significant performance degradation during batch processing. Upon investigation, you observe that your dataset consists of numerous small files due to frequent small-scale updates and incremental loads. How can these small files impact the performance of your Spark job, and what optimization strategy should you implement?

1. Spark automatically combines small files in memory at runtime, so small files don't generally affect query performance. No additional action is needed.

2. Small files only affect performance when using Parquet format, not Delta Lake. Switching file formats will solve the issue.

3. Spark has to open many file handles, causing excessive I/O overhead. You should apply file compaction to combine the small files into larger ones.

4. The presence of small files reduces data locality, causing Spark to send more data over the network. You should repartition your dataset using a higher partition count.

5. Small files lead to over-partitioning, which increases the job's shuffle stage. You should apply a repartition with fewer partitions.

24. You are working on a multi-tenant architecture where each tenant has their own isolated set of tables. You want to test a new feature in one tenant’s environment without affecting the production workload. The tables are built on Delta Lake, and you decide to use Delta Clone to create an isolated copy of the tables for testing. You want to ensure that your clone includes all the data and maintains the exact same schema as the source table but is physically independent. What type of Delta Clone should you use?

1. Time Travel Clone

2. Deep Clone

3. Shallow Clone

4. Partitioned Clone

25. You are designing a Delta Lake table to store web clickstream data for a large e-commerce website. The data includes columns such as user_id, session_id, page_viewed, click_timestamp, and country. The table will store billions of records, and queries will commonly filter by country and click_timestamp. Additionally, some analysts will perform user-level analysis on specific user_ids. What is the most appropriate partitioning strategy for the Delta table?

1. Partition by page_viewed because it has a moderate number of distinct values, improving performance for page-based queries.

2. Partition the table by the session_id column to ensure that each session’s data is stored together.

3. Partition the table by click_timestamp because this will help improve query performance for time-based analysis.

4. Partition the table by both country and click_timestamp to ensure queries that filter by time and country are efficient.

5. Partition the table by the user_id column because this will speed up user-level queries.

26. What is a recommended approach when designing a multiplex Bronze table for streaming workloads to handle late-arriving data efficiently?

1. Store late-arriving data in a separate table to avoid affecting the main data pipeline

2. Use Delta Lake’s time travel feature to continually rewrite history as late data arrives

3. Implement watermarking to handle late-arriving data while maintaining performance

4. Design the streaming process to discard any late-arriving data to ensure low latency

27. You are tasked with writing a large PySpark DataFrame to disk in Parquet format. To optimize the file size of each part-file, you wish to ensure that each file is approximately 256MB. Which of the following methods would help you manually control the size of the part-files while writing the DataFrame to disk?

1. df.rebalance().write.option("maxFileSize", 256MB).parquet("/path/to/output")

2. df.write.option("partSize", "256MB").parquet("/path/to/output")

3. df.coalesce(1).write.mode("overwrite").parquet("/path/to/output")

4. df.repartition(1000).write.option("maxRecordsPerFile", 100000).parquet("/path/to/output")

28. You are tasked with optimizing a large batch processing job that processes millions of records daily. The job takes significantly longer than expected, and you're required to improve performance by adjusting the way the data is partitioned and written to disk. Which of the following approaches will help optimize the batch job by improving data partitioning and writing efficiency? (Select two)

1. Use repartition(1) before writing to limit the number of output files to one.

2. Set the shuffle partitions to a large number, such as spark.sql.shuffle.partitions = 2000, to avoid excessive shuffling during the write process.

3. Coalesce the partitions to a smaller number right before writing using coalesce(10) for better I/O performance.

4. Increase the number of partitions using repartition(100) before writing to disk.

5. Use repartitionByRange("column_name") to partition the data based on a specific column with evenly distributed values.

29. You are responsible for deploying a production streaming job that must meet strict cost efficiency requirements, with a latency SLA of 5 seconds. Which of the following design choices would most effectively balance cost and latency for this streaming job?

1. Use a small fixed cluster size, irrespective of workload fluctuations, to reduce costs.

2. Disable auto-scaling and manually adjust the cluster size based on expected data load.

3. Configure the job to use stateful processing with a high state timeout to ensure minimal data loss.

4. Enable autoscaling for the cluster and adjust the micro-batch size to match the data arrival rate.

30. You are designing a streaming pipeline to process real-time user activity data using Delta Lake and Structured Streaming. The incoming events occasionally experience delays, resulting in late-arriving data. You need to ensure that these late events are properly incorporated into the Delta Lake table, with accurate aggregation and state management, while minimizing the need to reprocess the entire dataset. Which two methods would best address the handling of late-arriving data in this streaming pipeline? (Select two)

1. Re-process the entire Delta table from the beginning whenever late data arrives.

2. Use watermarking and update mode to manage state for late events.

3. Use update mode in Structured Streaming to directly update Delta Lake with late-arriving data.

4. Apply merge into the Delta table to capture late events.

5. Use append mode without watermarking to allow late data to be added without limits.

31. Your company has strict compliance requirements, and you need to track and audit all access to specific datasets stored in Delta Lake using Unity Catalog. The compliance team requires detailed lineage tracking to know who accessed what data, when, and any changes made to the dataset. You are asked to implement a solution that captures audit logs and data lineage for every operation performed on the sensitive dataset. Which configuration should you implement in Unity Catalog to meet the compliance and auditing requirements?

1. Enable Delta Lake’s time travel feature and use it to track historical changes to the dataset.

2. Use Databricks’ table access control feature to log access events in the Unity Catalog audit logs.

3. Enable audit logging in Unity Catalog and configure data lineage tracking at the catalog level for the dataset.

4. Use Delta Lake’s Optimize command with Z-ordering to automatically capture data lineage for audit purposes.

32. You are deploying a real-time streaming job in Databricks using Structured Streaming. The job must process data continuously from a Kafka source and write the results to a Delta table. To ensure high availability and fault tolerance, the job needs to be resilient against cluster failures or crashes. Which of the following is the most appropriate strategy to configure this Databricks Job?

1. Write to a Delta table without checkpointing, as Delta Lake provides automatic fault tolerance.

2. Enable "Auto Termination" for the cluster to restart automatically in case of failures.

3. Use a streaming trigger with a high processing interval to reduce the load on the cluster and avoid failures.

4. Enable checkpointing for the streaming query and configure task retries within the Databricks Job settings.

5. Run the streaming job as a batch process to avoid the complexities of streaming fault tolerance.

33. You are designing a multiplex bronze table in Delta Lake to handle streaming ingestion from multiple sources. These sources may evolve their schemas over time, adding or renaming fields. You want to ensure that your design can handle schema changes efficiently without causing issues in production or breaking downstream systems that depend on the bronze table. You also want to minimize the risk of data loss or inconsistencies. Which approach should you implement to handle schema evolution in the multiplex bronze table?

1. Enable automatic schema detection in the downstream silver table, so the silver table adapts to changes in the bronze table without manual intervention.

2. Disable schema enforcement and allow any schema changes from the source to pass through to the bronze table without validation.

3. Enable mergeSchema on write operations to the Delta Lake table so it can automatically adjust to new columns or schema changes.

4. Store all source streams in separate bronze tables to ensure that schema changes in one source do not affect others.

34. You want to programmatically trigger a run of an existing job in Databricks with job ID 5678 and retrieve the output of the run using the REST API. Which of the following sequence of REST API calls will correctly trigger the run and export the run output?

1. GET /api/2.1/jobs/trigger with job ID 5678, followed by GET /api/2.1/jobs/runs/output using the run ID

2. POST /api/2.1/jobs/trigger with job ID 5678, followed by GET /api/2.1/jobs/runs/get-log using the job ID

3. POST /api/2.1/jobs/run-now with job ID 5678, followed by GET /api/2.1/jobs/runs/get-output using the run ID

4. POST /api/2.1/jobs/run with job ID 5678, followed by POST /api/2.1/jobs/get-output using the job ID

35. You are tasked with deploying a large-scale data processing pipeline in Databricks that involves multiple Python modules shared across different teams. Each team is responsible for developing and testing a portion of the pipeline in their own environment (dev, test, prod). To standardize the deployment process, you want to consolidate these Python modules into reusable components, ensuring consistent dependencies across environments while minimizing manual intervention. Additionally, you need to ensure that teams can continue testing their individual modules without impacting others. Which is the best approach to adapt your existing notebook-based pipeline into one that uses Python files for dependencies, while maintaining version control and ensuring smooth deployment across environments?

1. Package all the Python modules into a single wheel file and install the wheel using the Databricks Libraries UI for each environment.

2. Use %run to import notebooks as dependencies for individual components of the pipeline, and set different environment variables to switch between environments.

3. Use Databricks Connect to manage dependencies between notebooks and Python files, enabling cross-environment compatibility without changes.

4. Refactor the Python modules, place them into a GitHub repository, and install them in each environment using Databricks Repos and pip install -e for live editing.

36. A data architect has directed that all new Delta Lake tables should be configured as external, unmanaged tables to ensure that data files remain stored in a specified cloud storage location rather than within the Databricks-managed storage layer. The data engineer must ensure compliance with this mandate. Which step should the data engineer follow when creating a new Delta Lake table to meet this requirement?

1. Use the LOCATION keyword in the CREATE TABLE statement to specify the cloud storage path for the data files.

2. Create a mount point for the cloud storage and rely on Delta Lake to automatically treat all tables as unmanaged.

3. Use the STORAGE keyword in the CREATE TABLE statement to indicate that the table will use external storage.

4. Use the EXTERNAL keyword in the CREATE TABLE statement to specify that the table is unmanaged.

5. Set the spark.sql.catalog.externalTables.location property to define the default location for all external tables.

37. You are designing a job to perform nightly ETL processing on a large dataset in Databricks. The job must be able to scale to handle high volumes of data while ensuring data consistency and fault tolerance. Which of the following job design patterns would best meet these requirements?

1. Single Long-Running Cluster with Manual Restart on Failure

2. Interactive Cluster with Manual Job Trigger

3. Job Cluster with Autopilot Scheduling

4. Jobs API with Cluster Pools and Retry Logic

38. A data engineering team is preparing to deploy a Databricks pipeline to production. The team wants to ensure that future updates to the pipeline do not introduce regressions. Which deployment strategy should they implement to achieve this goal?

1. Use a staging environment where changes can be tested before deploying to production.

2. Deploy changes directly to the production pipeline and roll back if errors occur

3. Implement CI/CD pipelines with automated tests and push directly to production after each successful build.

4. Run the production pipeline manually and visually inspect the results after each change.

5. Deploy changes to a different cluster type in production for validation.

39. You have successfully modularized your Databricks notebook by moving utility functions to a Python file, utils.py. You now need to test the Python file during development. How can you ensure that any changes made to utils.py are immediately reflected in the notebook without needing to restart the cluster?

1. Use the importlib.reload() function after making changes to the utils.py file and running the cell in the notebook.

2. Upload a new version of the Python file to DBFS each time it is changed, and restart the cluster to reflect the updates.

3. Enable the Auto-Restart feature for your cluster to automatically reload dependencies whenever there is a change in the DBFS.

4. Use the %reload magic command to reload the Python file each time it is updated.

40. You are transitioning a large-scale Databricks project from using Python Wheels to direct imports with relative paths for better maintainability. The project is divided into several submodules, and each submodule imports code from other submodules. After removing the Wheel packaging, you need to ensure that all modules can be imported using relative paths within the Databricks environment. What is the most appropriate step to adapt the project’s imports to relative paths?

1. Use Databricks Libraries to install the Python project as a custom library and retain the current import statements without making changes to the code.

2. Use the databricks-connect API to link the workspace with your local environment and let the relative imports resolve based on your local project structure.

3. Replace all imports across submodules with relative imports using . and .., and ensure that each submodule includes an init.py file to treat it as a package.

4. Rewrite the import statements to include the full Databricks file system paths, and keep the Wheel package installation intact for backward compatibility.

41. You are working on a Databricks project that uses Unity Catalog for centralized data governance across multiple workspaces. The goal is to ensure consistent access controls and auditing for all the data assets. You are tasked with setting up Unity Catalog to govern access to your data lakes. Which of the following actions correctly describes a step in implementing Unity Catalog for data governance?

1. CREATE DATABASE finance WITH UNITY CATALOG;

2. GRANT ALL PRIVILEGES ON DATABASE finance TO USER john_doe WITH GRANT OPTION;

3. CREATE CATALOG customer_data;

4. CREATE CATALOG finance_catalog USING 'delta';

42. You are managing a Delta table that stores user event logs from a mobile application. The data is partitioned by the event_date column, which records the date of the user activity. The table grows rapidly, and the business requires that data older than one year be archived to another storage location. Your goal is to implement an efficient archiving process that minimizes the amount of data scanned and moved while preserving recent data in the Delta table. Which of the following is the most efficient approach to archive data older than one year?

1. Use the OPTIMIZE command on the Delta table to compact the data, then copy the compacted files to an archive location for data older than one year.

2. Leverage the partitioning by event_date and use the COPY INTO command to transfer only the partitions older than one year to a separate storage location for archiving.

3. Use the VACUUM command with a retention period of one year to automatically archive older data into a separate Delta table.

4. Use the DELETE command with a WHERE clause that filters records older than one year, then write a separate process to store these deleted records in an archive.

43. What is the most effective strategy to optimize Delta tables for Databricks SQL when performing frequent queries with aggregate operations?

1. Create as many partitions as possible to maximize query parallelism across the table.

2. Always store data in uncompressed format to improve query speed.

3. Use Z-Ordering on columns frequently involved in WHERE clauses to optimize data skipping.

4. Apply file compaction after every write operation to minimize small file issues.

44. A retail company is processing real-time order data and needs to join it with a static table of customer information stored in Delta format. Each order has a timestamp, and customer data includes a valid_from and valid_to field, indicating when the customer was active. You are asked to implement a stream-static join that includes only orders made by customers who were active at the time of the order. Which approach is the best to ensure that only active customers at the time of the order are joined?

1. Use a simple inner join between the streaming order data and the static customer table on the customer_id and filter out inactive customers using a where clause.

2. Perform the stream-static join but load the static data as a stream to handle time-based conditions dynamically during the query.

3. Use a stream-static join and include the condition order.timestamp BETWEEN customer.valid_from AND customer.valid_to in the join clause.

4. Perform a cross join between the streaming data and static data and filter the results by checking customer activity within the streaming query's processing window.

45. You are tasked with setting up a complex data pipeline that involves multiple notebooks running in sequence. Each notebook performs a specific task such as data ingestion, transformation, and validation. You need to schedule this pipeline as a Databricks Job and ensure that the entire workflow runs in a defined order with error handling and retries for failures. What are the most appropriate ways to configure this job in Databricks? (Select two)

1. Use Airflow DAGs to call each Databricks notebook in sequence from an external orchestrator.

2. Use a Databricks cluster-scoped init script to automate notebook execution at the cluster level, ensuring that each notebook runs in sequence.

3. Use Delta Live Tables (DLT) to handle the execution order and scheduling of the pipeline, as DLT provides built-in orchestration for any type of task.

4. Create a single Databricks Job with multiple tasks where each task represents a notebook. Define task dependencies to enforce the order of execution.

5. Use Databricks Workflows to orchestrate the entire pipeline and configure task-level retries in case of failure.

46. You are working on a real-time customer order processing system. The order data is coming in as a stream from multiple sources, and you need to write the data into a Delta Lake table. Your goal is to ensure that each order is written exactly once to the Delta table, and updates to existing orders are processed efficiently. The system should also handle late-arriving data. Which approach should you use to design this solution?

1. Use a batch job to periodically update the Delta table, ensuring no duplicates.

2. Use a Delta Lake table and Structured Streaming with watermarking and upsert logic (MERGE INTO).

3. Use a non-transactional storage format like Parquet and rely on checkpointing in Structured Streaming.

4. Use a Delta Lake table and an append-only mode to store new orders as they arrive.

47. You are managing a Delta Lake table with important transactional data. For data backup and testing purposes, you decide to create a clone of the table. However, you're unsure whether to use a shallow clone or a deep clone. Your requirements include ensuring that the backup can survive if the source data is deleted or corrupted, and that the cloned data is immediately available for testing with minimal operational complexity. Which of the following statements best describes the difference between shallow and deep clones in Delta Lake and correctly identifies the most suitable cloning method based on your needs?

1. A shallow clone copies only the data files, while a deep clone copies both the data and the table metadata.

2. A deep clone creates a completely independent copy of the data and metadata, whereas a shallow clone only copies references to the data files.

3. A shallow clone creates an independent copy of the data, but relies on the source table’s metadata, whereas a deep clone copies only the table’s schema.

4. A shallow clone is slower to create than a deep clone because it needs to reference the source table's data files.

FAQs

1. What is the Databricks Certified Data Engineer Professional exam?

The Databricks Certified Data Engineer Professional exam validates your ability to build, manage, and optimize advanced data pipelines and workflows using the Databricks Lakehouse Platform.

2. How do I become a Databricks Certified Data Engineer Professional?

You need to pass the Databricks Certified Data Engineer Professional exam, which tests your expertise in ETL design, data modeling, Delta Lake optimization, and advanced SQL.

3. What are the prerequisites for the Databricks Certified Data Engineer Professional exam?

It is recommended that you hold the Databricks Certified Data Engineer Associate certification and have practical experience in data engineering and Databricks tools.

4. How much does the Databricks Certified Data Engineer Professional certification cost?

The exam costs $200 USD, though pricing may vary by region or currency.

5. How many questions are in the Databricks Certified Data Engineer Professional exam?

The exam includes 60 multiple-choice and multiple-select questions that must be completed within 120 minutes.

6. What topics are covered in the Databricks Certified Data Engineer Professional exam?

It covers Delta Lake architecture, data ingestion, transformation, optimization, job orchestration, and performance tuning.

7. How difficult is the Databricks Certified Data Engineer Professional exam?

It’s an advanced-level exam, requiring deep understanding of Databricks, Apache Spark, and complex data engineering workflows.

8. How long does it take to prepare for the Databricks Certified Data Engineer Professional exam?

Most candidates take 8–10 weeks to prepare, depending on their Databricks experience and familiarity with Spark and SQL.

9. What jobs can I get after earning the Databricks Certified Data Engineer Professional certification?

You can work as a Senior Data Engineer, Big Data Architect, ETL Engineer, or Cloud Data Specialist.

10. How much salary can I earn with a Databricks Certified Data Engineer Professional certification?

Professionals typically earn between $120,000–$160,000 per year, depending on their role, experience, and location.