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Data Engineer Associate · Domain 1: Databricks Intelligence Platform · 6% of the exam

Task 1.1: Understand the core components of the Databricks Data Intelligence Platform, such as its architecture, Delta Lake, and Unity Catalog.

The control plane and compute plane, workspaces and metastores, Delta Lake's transaction log, ACID writes and time travel, and Unity Catalog's three-level namespace and securable objects.

Study it

  • Control plane, compute plane, workspaces and the Unity Catalog metastore

    Lesson coming

  • Delta Lake: the transaction log, ACID writes, history and time travel

    Partly covered by: Transactions & ACID

  • Unity Catalog: the three-level namespace and securable objects

    Lesson coming

Sample questions

Try each one before opening the answer. Every option is explained, with the Databricks documentation page that proves it.

Question 1 · choose 1

A nightly job overwrote the Delta table sales.silver.orders with bad data, creating version 42. Dashboards and downstream jobs read the table by name, and all of them must see the version 41 contents again without anyone changing their queries. What should the data engineer run?

  1. ASELECT * FROM sales.silver.orders VERSION AS OF 41
  2. BVACUUM sales.silver.orders RETAIN 0 HOURS
  3. CRESTORE TABLE sales.silver.orders TO VERSION AS OF 41
  4. DDESCRIBE HISTORY sales.silver.orders LIMIT 1
Show the answer and why
  • ASELECT * FROM sales.silver.orders VERSION AS OF 41

    Incorrect

    A time travel query reads the old version for that one query only; the table's current version stays 42 for every other reader.

  • BVACUUM sales.silver.orders RETAIN 0 HOURS

    Incorrect

    VACUUM deletes data files that the current version no longer references, which would destroy the files needed to go back to version 41.

  • CRESTORE TABLE sales.silver.orders TO VERSION AS OF 41

    Correct

    RESTORE writes a new commit that returns the table to the state of version 41, so every reader that queries the table by name sees the earlier contents.

  • DDESCRIBE HISTORY sales.silver.orders LIMIT 1

    Incorrect

    DESCRIBE HISTORY is a read-only command; it changes nothing, so readers keep seeing version 42.

Every write to a Delta table creates a version in the transaction log. Time travel reads an old version for a single query, while RESTORE rolls the table itself back so all readers get the earlier state.

Question 2 · choose 1

A security reviewer asks where the virtual machines of a classic jobs cluster run in a Databricks workspace on AWS. What is the answer?

  1. AIn the control plane, next to the Databricks web application
  2. BIn the classic compute plane, inside the customer's own AWS account
  3. CIn the serverless compute plane, inside the Databricks account
  4. DIn the workspace storage bucket that holds notebooks and job results
Show the answer and why
  • AIn the control plane, next to the Databricks web application

    Incorrect

    The control plane holds the backend services and the web application that Databricks manages; data is processed in the compute plane.

  • BIn the classic compute plane, inside the customer's own AWS account

    Correct

    Classic compute resources run in your AWS account, in what Databricks calls the classic compute plane.

  • CIn the serverless compute plane, inside the Databricks account

    Incorrect

    The serverless compute plane runs serverless compute; classic clusters are created in your own account instead.

  • DIn the workspace storage bucket that holds notebooks and job results

    Incorrect

    The workspace storage bucket stores workspace system data such as notebook revisions and job results; it does not run compute.

Databricks splits a workspace into a control plane and a compute plane. Serverless compute runs in a compute plane in the Databricks account; classic compute runs in the customer's cloud account.

Question 3 · choose 1

A company has two Databricks workspaces in the same AWS region, one for engineering and one for analytics. Both must see the same catalogs, tables and access grants, managed in one place. What should the platform team do?

  1. ACreate a metastore for each workspace and copy the tables between them each night
  2. BShare the engineering tables to the analytics workspace through OpenSharing
  3. CKeep the tables in the DBFS root of one workspace and mount that path in the other
  4. DAttach both workspaces to the same Unity Catalog metastore
Show the answer and why
  • ACreate a metastore for each workspace and copy the tables between them each night

    Incorrect

    Separate metastores mean separate grants and duplicate data, which is the opposite of one governed view.

  • BShare the engineering tables to the analytics workspace through OpenSharing

    Incorrect

    OpenSharing shares data across platforms, clouds and regions; workspaces in the same region can simply use the same metastore.

  • CKeep the tables in the DBFS root of one workspace and mount that path in the other

    Incorrect

    DBFS root and mounts are legacy patterns without Unity Catalog governance, so grants would not be shared.

  • DAttach both workspaces to the same Unity Catalog metastore

    Correct

    A metastore can be linked to multiple workspaces in the same region, giving each workspace the same data view with access controls managed across them.

The Unity Catalog metastore is the governance container for catalogs, schemas and tables. Attaching it to several workspaces in one region gives them one shared, centrally governed view of the data.

Question 4 · choose 1

A job writing new Parquet data files to a Delta table crashes halfway through. Readers continue to see the table as it was before the job started. Which Delta Lake mechanism explains this?

  1. AA write is visible once its commit is recorded in the transaction log
  2. BDelta Lake writes into a temporary table and renames it when the job ends
  3. CDelta Lake locks the table so readers wait until the writer finishes
  4. DThe writer deletes its partial files right away when it detects the failure
Show the answer and why
  • AA write is visible once its commit is recorded in the transaction log

    Correct

    Files from a failed transaction are never added to the log, so they are not part of the table state; VACUUM can later remove them.

  • BDelta Lake writes into a temporary table and renames it when the job ends

    Incorrect

    Delta Lake writes data files into the table directory and commits them through the log; it does not swap table names.

  • CDelta Lake locks the table so readers wait until the writer finishes

    Incorrect

    Databricks uses optimistic concurrency control without locks; readers get a snapshot instead of waiting.

  • DThe writer deletes its partial files right away when it detects the failure

    Incorrect

    Uncommitted files can remain in the directory; they are ignored because the log does not reference them.

The transaction log decides what the table contains. Each commit adds a version that references its files, so a write is all or nothing for readers.

Question 5 · choose 1

In a medallion architecture, customer and transaction records are cleaned, validated, deduplicated and joined into a detailed customer_transactions dataset that data scientists use for analysis. Where should this dataset be held?

  1. ABronze
  2. BGold
  3. CSilver
  4. DA landing volume for raw files
Show the answer and why
  • ABronze

    Incorrect

    Bronze holds raw, unvalidated data, with only minimal validation.

  • BGold

    Incorrect

    Gold holds aggregated, business-level datasets such as average spend per customer, built for business users.

  • CSilver

    Correct

    Silver is the layer for cleaning and validation; it keeps detailed records that analysts and data scientists use.

  • DA landing volume for raw files

    Incorrect

    A volume stores files before ingestion; it is not a layer of validated tables.

Data improves as it moves from bronze (raw) to silver (cleaned and validated) to gold (modeled and aggregated). Detailed, validated joins of entities belong in silver.

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