Databricks-Certified-Data-Engineer-Associate Databricks Certified Data Engineer Associate Exam Questions and Answers

The command DESCRIBE DATABASE customer360; will return the location of the database customer360, along with its comment and properties. This command is an alias for DESCRIBE SCHEMA customer360;, which can also be used to get the same information. The other commands will either drop the database, alter its properties, or use it as the current database, but will not return its location12. References:

DESCRIBE DATABASE | Databricks on AWS

DESCRIBE DATABASE - Azure Databricks - Databricks SQL

This question’s options do not include the most precise Unity Catalog answer, which would normally be the MANAGE privilege on the schema, because Databricks documents that MANAGE allows a principal to grant and revoke privileges on an object without automatically granting all data-access privileges on that object. However, since MANAGE is not one of the answer choices, the best available answer is D, Schema Owner . Databricks states that schema owners can grant and revoke permissions on the schema, and schema-level administration is a documented responsibility of the schema owner. Option A is incorrect because USE CATALOG and USE SCHEMA only allow object access/navigation and do not confer privilege-management rights. Option B is too broad because a catalog owner governs the entire catalog scope, not just one schema. Option C is too narrow because a table owner controls only one table, not various objects across a schema. So, among the choices provided, Schema Owner is the closest Databricks-aligned answer, though the cleanest real-world implementation would be MANAGE on the schema .

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Lakeflow Jobs provides task-level Run if conditions such as All succeeded, All done, At least one failed, and All failed. No single Run if condition directly represents “A succeeded and B failed” when Task C depends directly on both tasks. The required outcome can be modeled with two guarded dependency branches: one gateway proceeds only after Task A succeeds, and another proceeds only after Task B fails. Task C then uses All succeeded against those two successful gateway tasks. A negative dependency is not a supported dependency type. Task values pass arbitrary application values and do not automatically represent task outcomes. Notebook widgets are task parameters rather than dependency-state conditions. Therefore, the two-chain configuration described in option B correctly represents the required conjunction.

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Databricks recommends managed tables when you want the platform to control both the table metadata and the underlying storage lifecycle. For Unity Catalog managed tables, Databricks manages storage layout and applies platform-managed optimization features over time. Databricks also documents that when you drop a managed table , the underlying cloud data is deleted automatically after the managed retention period, which simplifies cleanup and reduces storage administration. That behavior matches the requirement exactly. External tables, by contrast, are used when you want to retain direct control over the storage path and lifecycle. Databricks explicitly states that dropping an external table removes only the metadata and does not delete the underlying files . Foreign tables are for federation scenarios against external systems, not for Bronze ingestion storage managed by Databricks. Temporary views also do not provide the desired governed lifecycle. Because the team wants Databricks-managed storage, managed retention, and simplified lifecycle handling, managed tables are the correct choice for these Bronze ingestion tables.

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Databricks Repos is a visual Git client and API in Databricks that supports common Git operations such as cloning, committing, pushing, pulling, and branch management. Databricks Notebooks versioning is a legacy feature that allows users to link notebooks to GitHub repositories and perform basic Git operations. However, Databricks Notebooks versioning does not support the use of multiple branches for development work, which is an advantage of using Databricks Repos. With Databricks Repos, users can create and manage branches for different features, experiments, or bug fixes, and merge, rebase, or resolve conflicts between them. Databricks recommends using a separate branch for each notebook and following data science and engineering code development best practices using Git for version control, collaboration, and CI/CD. References: Git integration with Databricks Repos - Azure Databricks | Microsoft Learn, Git version control for notebooks (legacy) | Databricks on AWS, Databricks Repos Is Now Generally Available - New ‘Files’ Feature in …, Databricks Repos - What it is and how we can use it | Adatis.

The command databricks bundle deploy deploys the bundle’s local files, artifacts, and resource definitions to the configured remote Databricks workspace. Databricks documents this command as the deployment operation for Declarative Automation Bundles, and a specific target can be selected with the -t or --target option. The validate command checks whether the bundle configuration is valid but does not create or update workspace resources. The run command executes a resource that has already been deployed; it is not the deployment step. The init command creates a new bundle project from a template, while bundle deployment is not a valid command combination. Because the question asks for the single command that sends local bundle assets to the target workspace, option C is correct.

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In a Databricks customer ' s cloud account, the primary elements stored include:

Data: This is the central type of content stored in the customer ' s cloud account. Data might include various datasets, tables, and files that are used and managed through Databricks platforms.

Notebooks: These are also stored within a customer ' s cloud account. Notebooks include scripts, notes, and other information necessary for data analysis and processing tasks.

Cluster management metadata is indeed managed through the cloud, but it ' s primarily handled by Databricks rather than stored directly in the customer ' s account. The Databricks web application itself is not stored within the customer ' s cloud account; rather, it ' s a service provided by Databricks.

The engineer should use Repair run . A repair reruns unsuccessful tasks as part of the original job run while preserving the successful status of tasks that do not need to be executed again. In this scenario, Tasks 1 and 2 remain successful, Task 3 is rerun after its problem is corrected, and Task 4 can execute after its dependency succeeds. Run now starts a separate job run and normally executes the workflow from its beginning. Cloning a task creates another task definition and does not resume the failed run. Reset job is not the appropriate Lakeflow Jobs recovery operation. Databricks also notes that repaired tasks should use idempotent write logic where possible because a failed task might have produced partial output before failing. Therefore, option C correctly resumes the workflow without unnecessarily repeating the successful upstream tasks.

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The correct command to grant the necessary permission on the entire database to the new team is to use the GRANT USAGE command. The GRANT USAGE command grants the principal the ability to access the securable object, such as a database, schema, or table. In this case, the securable object is the database customers, and the principal is the group team. By granting usage on the database, the team will be able to see what tables already exist in the database. Option E is the only option that uses the correct syntax and the correct privilege type for this scenario. Option A uses the wrong privilege type (VIEW) and the wrong securable object (CATALOG). Option B uses the wrong privilege type (CREATE), which would allow the team to create new tables in the database, but not necessarily see the existing ones. Option C uses the wrong securable object (CATALOG) and the wrong principal (customers). Option D uses the wrong securable object (team) and the wrong principal (customers). References: GRANT, Privilege types, Securable objects, Principals

Pipeline A has a driver-side failure because collect() transfers every row to the driver process. Databricks states that collect() should be used only when the result is expected to be small. For a 100 GB dataset, the preferred correction is to remove the full collection and use distributed processing, aggregation, sampling, or limit; increasing driver capacity alone is not a durable solution. Pipeline B is an executor-side problem during a shuffle-intensive join. Increasing spark.sql.shuffle.partitions can divide the shuffled data into smaller task partitions, while workers with more memory per core can provide additional executor memory. Increasing the number of executors does not solve Pipeline A’s driver bottleneck, and increasing driver memory does not address Pipeline B’s executor failures. Therefore, option D correctly distinguishes the affected Spark components and appropriate remedies.

The data engineering team can use the spark.table method to access the Delta table sales in PySpark. This method returns a DataFrame representation of the Delta table, which can be used for further processing or testing. The spark.table method works for any table that is registered in the Hive metastore or the Spark catalog, regardless of the file format1. Alternatively, the data engineering team can also use the DeltaTable.forPath method to load the Delta table from its path2. References: 1: SparkSession | PySpark 3.2.0 documentation 2: Welcome to Delta Lake’s Python documentation page — delta-spark 2.4.0 documentation

Reading a Unity Catalog table requires privileges at all relevant levels of its three-part namespace. The group needs USE CATALOG on corp_marketing, USE SCHEMA on campaigns, and SELECT on email_stats. These privileges allow users to resolve the catalog and schema and read the table without granting permission to create or modify objects. Option A omits USE CATALOG, so table access is incomplete. Option B unnecessarily grants CREATE SCHEMA, violating the requirement that the group must not create objects. Option D omits USE CATALOG and grants MODIFY, which would permit data changes. Unity Catalog follows a hierarchical permissions model, but possession of SELECT alone is insufficient without the required usage privileges on the parent containers. Therefore, the least-privilege sequence in option C is correct.

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Unity Catalog organizes data objects through a three-level namespace consisting of catalog, schema, and object. To query sales_catalog.market_data.summary, the analyst requires USE CATALOG on sales_catalog, USE SCHEMA on market_data, and SELECT on the summary view. Granting SELECT on the view alone is insufficient when either parent usage privilege is missing. The analyst does not normally require access to the underlying tables queried by the view because the view owner’s privileges are used to resolve those objects. A workspace or cluster is not part of the Unity Catalog securable hierarchy for resolving the view name. Storage credentials and external locations govern cloud-storage access rather than ordinary view-query permissions. Therefore, the engineer should verify privileges in the order catalog, schema, and view, making option B correct.

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 To append a new record to an existing Delta table, you can use the INSERT INTO statement with the VALUES clause. This statement will insert one or more rows into the table with the specified values. Option A is the only code block that follows this syntax correctly. Option B is incorrect, as it uses the UNION operator, which will return a new table that is the union of two tables, not append to an existing table. Option C is incorrect, as it uses the INSERT VALUES statement, which is not a valid SQL syntax. Option D is incorrect, as it uses the UPDATE statement, which will modify existing rows in the table, not append new rows. Option E is incorrect, as it uses the UPDATE VALUES statement, which is also not a valid SQL syntax. References: Insert data into a table using SQL | Databricks on AWS, Insert data into a table using SQL - Azure Databricks, Delta Lake Quickstart - Azure Databricks

One of the benefits of the Databricks Lakehouse Platform embracing open source technologies is that it avoids vendor lock-in. This means that customers can use the same open source tools and frameworks across different cloud providers, and migrate their data and workloads without being tied to a specific vendor. The Databricks Lakehouse Platform is built on open source projects such as Apache Spark™, Delta Lake, MLflow, and Redash, which are widely used and trusted by millions of developers. By supporting these open source technologies, the Databricks Lakehouse Platform enables customers to leverage the innovation and community of the open source ecosystem, and avoid the risk of being locked into proprietary or closed solutions. The other options are either not related to open source technologies (A, B, C, D), or not benefits of the Databricks Lakehouse Platform (A, B). References: Databricks Documentation - Built on open source, Databricks Documentation - What is the Lakehouse Platform?, Databricks Blog - Introducing the Databricks Lakehouse Platform.

DataFrame.dropna() removes rows containing NULL or NaN values. Its default how= " any " behavior removes a row when any column included in the specified subset is NULL. By passing [ " customer_email " , " customer_phone " ] as the subset, the operation removes a record when either required field is missing, while ignoring NULL values in unrelated columns. Option B can produce the same filtering result, but it uses two chained where() calls and therefore does not meet the single-method-call requirement. Option C uses how= " all " and would remove a row only when all evaluated columns are NULL. Option D contains one filter() operation but requires multiple column-function calls. Consequently, option A is the direct PySpark method designed for this requirement.

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 Option A is the correct answer because it uses the FILTER higher-order function correctly to filter out employees with more than 5 years of experience from the array column “employees”. It applies a lambda function i - > i.years_exp > 5 that checks if the years of experience of each employee in the array is greater than 5. If this condition is met, the employee is included in the new array column “exp_employees”.

The use of higher-order functions like FILTER can be referenced from Databricks documentation on Higher-Order Functions.

 To grant full permissions on a table to a user or a group, you can use the GRANT ALL PRIVILEGES ON TABLE statement. This statement will grant all the possible privileges on the table, such as SELECT, CREATE, MODIFY, DROP, ALTER, etc. Option A is the only code block that follows this syntax correctly. Option B is incorrect, as it does not grant all the possible privileges on the table, but only a subset of them. Option C is incorrect, as it only grants the SELECT privilege on the table, which is not enough to fully manage the project. Option D is incorrect, as it grants the USAGE privilege on the table, which is not a valid privilege for tables. Option E is incorrect, as it grants all the privileges on the table team to the user or group sales, which is the opposite of what the question asks. References: Grant privileges on a table using SQL | Databricks on AWS, Grant privileges on a table using SQL - Azure Databricks, SQL Privileges - Databricks

The only option that is stored in the Databricks customer’s cloud account is data. Data is stored in the customer’s cloud storage service, such as AWS S3 or Azure Data Lake Storage. The customer has full control and ownership of their data and can access it directly from their cloud account.

Option A is not correct, as the Databricks web application is hosted and managed by Databricks on their own cloud infrastructure. The customer does not need to install or maintain the web application, but only needs to access it through a web browser.

Option B is not correct, as the cluster management metadata is stored and managed by Databricks on their own cloud infrastructure. The cluster management metadata includes information such as cluster configuration, status, logs, and metrics. The customer can view and manage their clusters through the Databricks web application, but does not have direct access to the cluster management metadata.

Option C is not correct, as the repos are stored and managed by Databricks on their own cloud infrastructure. Repos are version-controlled repositories that store code and data files for Databricks projects. The customer can create and manage their repos through the Databricks web application, but does not have direct access to the repos.

Option E is not correct, as the notebooks are stored and managed by Databricks on their own cloud infrastructure. Notebooks are interactive documents that contain code, text, and visualizations for Databricks workflows. The customer can create and manage their notebooks through the Databricks web application, but does not have direct access to the notebooks.

Databricks Architecture

Databricks Data Sources

Databricks Repos

[Databricks Notebooks]

[Databricks Data Engineer Professional Exam Guide]

databricks bundle validate should be run first because it checks whether the bundle configuration files are syntactically valid and reports configuration warnings. After validation succeeds, databricks bundle deploy creates or updates the bundle-defined resources and uploads the required artifacts to the selected workspace target. The final command, databricks bundle run, starts a deployed job or Lakeflow pipeline by using its resource key. bundle init creates a new project from a template and is not the validation step for an already developed bundle. bundle sync synchronizes files for development workflows but does not replace a complete deployment. The commands bundle execute, bundle check, bundle upload, and bundle start are not the appropriate command sequence. Therefore, option B is correct.

The File Arrival trigger and Auto Loader perform separate, complementary functions. The trigger monitors the configured storage location and starts the Lakeflow Job after detecting new files. After the notebook starts, Auto Loader examines its own checkpoint and file-tracking state to determine which files have not yet been committed successfully. This separation provides incremental processing and exactly-once ingestion behavior. With availableNow=True, Auto Loader processes all data available when the query starts and then stops, allowing the job compute to terminate and control costs. File Notification mode is not required solely because a File Arrival trigger is used. Disabling checkpoints would remove progress tracking and could cause duplicate processing. The trigger also does not eliminate the need to configure the Auto Loader source path. Therefore, option A is correct.

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Option D uses the business-key columns as the subset for duplicate comparison. Databricks documents that DataFrame.dropDuplicates can optionally accept a list of columns and then removes rows that are duplicates with respect to only those columns. Therefore, differing ingestion_timestamp values do not prevent records with the same customer_id and email from being treated as duplicates. Calling distinct() compares complete rows, so timestamp differences would preserve multiple records. Selecting only customer_id and email before distinct would remove every other column from the Silver result. The groupBy and max expression calculates a latest timestamp per key, but it changes the output shape and does not preserve a complete source record unless additional logic is added. For the stated requirement, option D is the direct and correct operation.

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To include a property indicating that a table contains personally identifiable information (PII), the TBLPROPERTIES keyword is used in SQL to add metadata to a table. The correct syntax to define a table property for PII is as follows:

CREATE TABLE customersInFrance

USING DELTA

TBLPROPERTIES ( ' PII ' = ' true ' )

AS

SELECT id,

firstName,

lastName

FROM customerLocations

WHERE country = ' FRANCE ' ;

The TBLPROPERTIES ( ' PII ' = ' true ' ) line correctly sets a table property that tags the table as containing personally identifiable information. This is in accordance with organizational policies for handling sensitive information.

he approach that can be used to identify the owner of new_table is to review the Owner field in the table’s page in Data Explorer. Data Explorer is a web-based interface that allows users to browse, create, and manage data objects such as tables, views, and functions in Databricks1. The table’s page in Data Explorer provides various information about the table, such as its schema, partitions, statistics, history, and permissions2. The Owner field shows the name and email address of the user who created or owns the table3. The data engineer can use this information to contact the table owner and request for permission to access the table.

The other options are not correct or reliable for identifying the owner of new_table. Reviewing the Permissions tab in the table’s page in Data Explorer can show the users and groups who have access to the table, but not necessarily the owner4. Reviewing the Owner field in the table’s page in the cloud storage solution can be misleading, as the owner of the data files may not be the same as the owner of the table5. There is a way to identify the owner of the table, as explained above, so option E is false.

1: Data Explorer | Databricks on AWS

2: Table details | Databricks on AWS

3: Set owner when creating a view in databricks sql - Databricks - 9978

4: Table access control | Databricks on AWS

5: External tables | Databricks on AWS

The Continuous Pipeline Mode for Delta Live Tables allows the pipeline to run continuously and process data as it arrives. This mode is suitable for streaming ingest and CDC workloads that require low-latency updates. The Development mode for Delta Live Tables allows the pipeline to run on a dedicated cluster that is not shared with other pipelines. This mode is useful for testing and debugging the pipeline logic before deploying it to production. Therefore, the correct answer is B, because the pipeline will run continuously on a dedicated cluster until it is manually stopped, and the compute resources will be released only after the pipeline is shut down. References: Databricks Documentation - Configure pipeline settings for Delta Live Tables, Databricks Documentation - Continuous vs. triggered pipeline execution, Databricks Documentation - Development vs. production mode.

 The keyword that can be used to compact the small files associated with a Delta table is OPTIMIZE. The OPTIMIZE command performs file compaction on a Delta table by rewriting a set of small files into a set of larger files1. This can improve the performance of queries that scan the table by reducing the number of files that need to be read and the amount of metadata that needs to be processed1. The OPTIMIZE command can also optionally sort the data within each file by a given set of columns, which can further improve the query performance by enabling data skipping and predicate pushdown1. The OPTIMIZE command can be applied to the whole table or to a specific partition of the table1.

The other keywords are not suitable for compacting the small files associated with a Delta table. REDUCE is a keyword used in the SQL syntax for aggregating data using a user-defined function2. COMPACTION is not a valid keyword in SQL or Python. REPARTITION is a keyword used in the Python syntax for changing the number of partitions of a DataFrame or an RDD3. VACUUM is a keyword used to remove files that are no longer referenced by a Delta table and are older than a retention threshold4.

1: OPTIMIZE | Databricks on AWS

2: REDUCE | Databricks on AWS

3: repartition | Databricks on AWS

4: VACUUM | Databricks on AWS

Option A is the correct answer because it shows the result of an INNER JOIN between the two tables. An INNER JOIN returns only the rows that have matching values in both tables based on the join condition. In this case, the join condition is ON a.customer_id = c.customer_id, which means that only the rows that have the same customer ID in both tables will be included in the output. The output will have four columns: customer_id, name, account_id, and overdraft_amt. The output will have four rows, corresponding to the four customers who have accounts in the account table.

The use of INNER JOIN can be referenced from Databricks documentation on SQL JOIN or from other sources like W3Schools or GeeksforGeeks.

A table is a data entity that is stored in a physical location and can be accessed by other data engineers in other sessions. A table can be created from one or more tables using the CREATE TABLE or CREATE TABLE AS SELECT commands. A table can also be registered from an existing DataFrame using the spark.catalog.createTable method. A table can be queried using SQL or DataFrame APIs. A table can also be updated, deleted, or appended using the MERGE INTO command or the DeltaTable API. References:

Create a table

Create a table from a query result

Register a table from a DataFrame

[Query a table]

[Update, delete, or merge into a table]

JSON data is a text-based format that represents data as a collection of name-value pairs. By default, when Auto Loader infers the schema of JSON data, it treats all columns as strings. This is because JSON data can have varying data types for the same column across different files or records, and Auto Loader does not attempt to reconcile these differences. For example, a column named “age” may have integer values in some files, but string values in others. To avoid data loss or errors, Auto Loader infers the column as a string type. However, Auto Loader also provides an option to infer more precise column types based on the sample data. This option is called cloudFiles.inferColumnTypes and it can be set to true or false. When set to true, Auto Loader tries to infer the exact data types of the columns, such as integers, floats, booleans, or nested structures. When set to false, Auto Loader infers all columns as strings. The default value of this option is false. References: Configure schema inference and evolution in Auto Loader, Schema inference with auto loader (non-DLT and DLT), Using and Abusing Auto Loader’s Inferred Schema, Explicit path to data or a defined schema required for Auto loader.

A Gold table is a table that contains highly refined and aggregated data that powers analytics, machine learning, and production applications. It represents data that has been transformed into knowledge, rather than just information. A Gold table is typically the final output of a medallion lakehouse architecture, where data flows from Bronze to Silver to Gold tables, with each layer improving the structure and quality of data. A job that queries aggregated data designed to feed into a dashboard is an example of a data workload that will utilize a Gold table as its source, as it requires data that is ready for consumption and analysis. The other options are either data workloads that will use a Bronze or Silver table as their source, or data workloads that will produce a Gold table as their output. References: Databricks Documentation - What is the medallion lakehouse architecture?, Databricks Documentation - What is a Medallion Architecture?, K21Academy - Delta Lake Architecture & Azure Databricks Workspace.

When migrating to Delta Live Tables (DLT) with a data pipeline that involves different programming languages across various data layers, the migration does not require unifying the pipeline into a single language. Delta Live Tables support multi-language pipelines, allowing data engineers and data analysts to work in their preferred languages, such as Python for data engineering tasks (raw, bronze, and silver layers) and SQL for data analytics tasks (gold layer). This capability is particularly beneficial in collaborative settings and leverages the strengths of each language for different stages of data processing.

 Delta Live Tables expectations are optional clauses that apply data quality checks on each record passing through a query. An expectation consists of a description, a boolean statement, and an action to take when a record fails the expectation. The ON VIOLATION clause specifies the action to take, which can be one of the following: warn, drop, or fail. The drop action means that invalid records are dropped from the target dataset before data is written to the target. The failure is reported as a metric for the dataset, which can be viewed by querying the Delta Live Tables event log. The event log contains information such as the number of records that violate an expectation, the number of records dropped, and the number of records written to the target dataset. References:

Manage data quality with Delta Live Tables

Monitor Delta Live Tables pipelines

Delta Live Tables SQL language reference

Option D matches the heterogeneous sources and governance requirements. A relational database, object storage, and Kafka require source-appropriate ingestion configurations rather than a single connector attempting to handle every source. Database ingestion can use incremental or change-data-capture processing, Amazon S3 files can use file-oriented ingestion, and Kafka requires a streaming connector. Publishing the outputs into Unity Catalog schemas provides centralized permissions, discovery, and governance boundaries. Supported Databricks ingestion workloads also record lineage between source and destination objects in Unity Catalog. Delta table history and time travel provide access to earlier table versions when the required transaction-log and data-file retention settings are maintained. Disabling version history or repeatedly performing complete reloads would weaken auditability and increase processing overhead. Therefore, the separate, incrementally processed, Unity Catalog-governed design in option D is correct.

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 Databricks cluster pools are a set of idle, ready-to-use instances that can reduce cluster start and auto-scaling times. This is useful for scenarios where a data team needs to run an automated report as quickly as possible, without waiting for the cluster to launch or scale up. Cluster pools can also help save costs by reusing idle instances across different clusters and avoiding DBU charges for idle instances in the pool. References: Best practices: pools | Databricks on AWS, Best practices: pools - Azure Databricks | Microsoft Learn, Best practices: pools | Databricks on Google Cloud

 An external table is a table that is defined in the metastore and points to an existing location in the storage system. When you drop an external table, only the metadata is deleted from the metastore, but the data files are not deleted from the storage system. This is because external tables are meant to be shared by multiple applications and users, and dropping them should not affect the data availability. On the other hand, a managed table is a table that is defined in the metastore and also managed by the metastore. When you drop a managed table, both the metadata and the data files are deleted from the metastore and the storage system, respectively. This is because managed tables are meant to be exclusive to the application or user that created them, and dropping them should free up the storage space. Therefore, the correct answer is C, because the table was external and only the metadata was deleted when the table was dropped. References: Databricks Documentation - Managed and External Tables, Databricks Documentation - Drop Table

Unity Catalog attribute-based access control policies provide centralized, tag-driven governance. Administrators define policies at a catalog or schema scope and use governed tags to identify the tables or columns to which the policies apply. When matching tags are assigned to current or future objects, the applicable policy is evaluated automatically, avoiding repetitive manual attachment of filters and masks to individual tables. This approach improves scalability and consistency when many objects require the same protection rules. It is important that the policy applies to objects matching its tag conditions, rather than indiscriminately to every object. The other choices incorrectly describe supported object types, multiple-filter behavior, or implementation languages. Databricks specifically positions attribute-based access control as the centralized approach for consistently applying row filtering and column masking across many governed tables. Therefore, option A is correct.

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The STREAM function is used to process data from a streaming live table or view, which is a table or view that contains data that has been added only since the last pipeline update. Streaming live tables and views are stateful, meaning that they retain the state of the previous pipeline run and only process new data based on the current query. This is useful for incremental processing of streaming or batch data sources. The customers table in the query is a streaming live table, which means that it contains the latest data from the source. The STREAM function enables the query to read the data from the customers table incrementally and create another streaming live table named loyal_customers, which contains the customer IDs of the customers with high loyalty level. References: Difference between LIVE TABLE and STREAMING LIVE TABLE, CREATE STREAMING TABLE, Load data using streaming tables in Databricks SQL.

The COPY INTO statement is an idempotent operation, which means that it will skip any files that have already been loaded into the target table1. This ensures that the data is not duplicated or corrupted by multiple attempts to load the same file. Therefore, if the data engineer runs the same command every day without specifying the names of the files to be copied with the FILES keyword or a glob pattern with the PATTERN keyword, the statement will only copy the first file that matches the source location and ignore the rest. To avoid this problem, the data engineer should either use the FILES or PATTERN keywords to filter the files to be copied based on the date or some other criteria, or delete the files from the source location after they are copied into the table2. References: 1: COPY INTO | Databricks on AWS 2: Get started using COPY INTO to load data | Databricks on AWS

In Unity Catalog, the Metastore Admin role has the highest level of authority within a metastore and is responsible for governing all data assets registered in that metastore. Metastore admins can transfer ownership of catalogs , manage privileges across all securable objects (catalogs, schemas, tables, views), and administer storage credentials, external locations, and Delta Sharing objects such as shares and recipients. This makes the role essential when a platform owner departs and continuity must be maintained at an organizational level. Workspace admins (option B) manage workspace-level settings but do not automatically have authority over Unity Catalog ownership unless explicitly granted. Catalog owners (option D) are limited to a single catalog and cannot perform actions across the entire metastore. Account admins (option A) operate at the account level and are primarily responsible for creating metastores and assigning admins, not for day-to-day governance within an existing metastore. Databricks documentation clearly defines the Metastore Admin as the role required to centrally manage ownership, privileges, and data sharing across the metastore in Databricks.

https://spark.apache.org/docs/latest/api/python/reference/pyspark.ss/api/pyspark.sql.streaming.DataStreamWriter.trigger.html

The best action that the data engineer can perform to improve the start up time for the clusters used for the Job is to use clusters that are from a cluster pool. A cluster pool is a set of idle clusters that can be used by jobs or interactive sessions. By using a cluster pool, the data engineer can avoid the cluster creation time and reduce the latency of the tasks. Cluster pools also offer cost savings and resource efficiency, as they can be shared by multiple users and jobs.

Option A is not relevant, as endpoints available in Databricks SQL are used for creating and managing SQL analytics workloads, not for improving cluster start up time.

Option B is not correct, as jobs clusters and all-purpose clusters have similar start up times. Jobs clusters are clusters that are dedicated to run a single job and are terminated when the job is completed. All-purpose clusters are clusters that can be used for multiple purposes, such as interactive sessions, notebooks, or multiple jobs. Both types of clusters can benefit from using a cluster pool.

Option C is not advisable, as configuring the clusters to be single-node will reduce the parallelism and performance of the tasks. Single-node clusters are clusters that have only one worker node and are typically used for testing or development purposes. They are not suitable for running production jobs that require high scalability and fault tolerance.

Option E is not helpful, as configuring the clusters to autoscale for larger data sizes will not affect the start up time of the clusters. Autoscaling is a feature that allows clusters to dynamically adjust the number of worker nodes based on the workload. It can help optimize the resource utilization and cost efficiency of the clusters, but it does not speed up the cluster creation process.

Cluster Pools

Jobs

Clusters

[Databricks Data Engineer Professional Exam Guide]

The correct command to create a new table that contains all records from two tables without duplicate records is to use the UNION operator. The UNION operator combines the results of two queries and removes any duplicate rows. The INNER JOIN, OUTER JOIN, and MERGE operators do not remove duplicate rows, and the INTERSECT operator only returns the rows that are common to both tables. Therefore, option B is the only correct answer. References: Databricks SQL Reference - UNION, Databricks SQL Reference - JOIN, Databricks SQL Reference - MERGE, [Databricks SQL Reference - INTERSECT]

This approach would allow the data engineering team to use the existing SQL program and add some logic to control the execution of the final query based on the day of the week. They could use the datetime module in Python to get the current date and check if it is a Sunday. If so, they could run the final query, otherwise they could skip it. This way, they could schedule the program to run every day without changing the data model or the source table. References: PySpark SQL Module, Python datetime Module, Databricks Jobs

Option C extracts each JSON field into a separate Silver-table column and casts age to the appropriate integer type. get_json_object accepts a JSON string and a JSONPath expression rooted at $; paths such as $.user_id and $.age therefore identify the required top-level fields correctly. This produces analytics-ready columns and prevents downstream queries from repeatedly parsing the original JSON string. Option A returns one nested struct and incorrectly defines age as STRING, so further projection or casting would still be required. Option B attempts field notation directly on a STRING column, which is not valid until the JSON has been parsed into a structured type. Option D omits the required $ JSONPath root and leaves age uncast. Therefore, option C most completely standardizes the source data for the Silver layer.

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 The VACUUM command is used to remove files that are no longer referenced by a Delta table and are older than the retention threshold1. The default retention period is 7 days2, but it can be changed by setting the delta.logRetentionDuration and delta.deletedFileRetentionDuration configurations3. If the VACUUM command was run on the table with a retention period shorter than 3 days, then the data files that were needed to restore the table to a 3-day-old version would have been deleted. The other commands do not delete data files from the table. The TIME TRAVEL command is used to query a historical version of the table4. The DELETE HISTORY command is not a valid command in Delta Lake. The OPTIMIZE command is used to improve the performance of the table by compacting small files into larger ones5. The HISTORY command is used to retrieve information about the operations performed on the table. References: 1: VACUUM | Databricks on AWS 2: Work with Delta Lake table history | Databricks on AWS 3: [Delta Lake configuration | Databricks on AWS]  4: Work with Delta Lake table history - Azure Databricks 5: [OPTIMIZE | Databricks on AWS] : [HISTORY | Databricks on AWS]

For large-scale batch ETL workloads , Databricks documentation recommends using job clusters that are created specifically for a job run and terminated automatically when the job completes. A job cluster with autoscaling enabled provides the best balance of performance, reliability, and cost efficiency for long-running nightly pipelines. Autoscaling allows the cluster to dynamically add or remove worker nodes based on the workload demands, ensuring sufficient parallelism to process very large JSON datasets efficiently while avoiding overprovisioning when demand decreases. This is especially important when processing raw data into Delta tables, where shuffle-heavy transformations and writes benefit from multiple workers. Single-node clusters (option B) are not suitable for very large volumes of data and risk excessive runtimes or job failures. High-concurrency clusters (option C) are optimized for interactive and concurrent SQL queries, not long-running batch ETL jobs. Always-on all-purpose clusters (option D) increase costs unnecessarily and are intended for interactive development, not scheduled production pipelines. Databricks best practices clearly position autoscaling job clusters as the preferred solution for reliable, cost-effective batch ETL in production on Databricks.