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
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?
ASELECT * FROM sales.silver.orders VERSION AS OF 41
BVACUUM sales.silver.orders RETAIN 0 HOURS
CRESTORE TABLE sales.silver.orders TO VERSION AS OF 41
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.
A security reviewer asks where the virtual machines of a classic jobs cluster run in a Databricks workspace on AWS. What is the answer?
AIn the control plane, next to the Databricks web application
BIn the classic compute plane, inside the customer's own AWS account
CIn the serverless compute plane, inside the Databricks account
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.
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?
ACreate a metastore for each workspace and copy the tables between them each night
BShare the engineering tables to the analytics workspace through OpenSharing
CKeep the tables in the DBFS root of one workspace and mount that path in the other
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.
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?
AA write is visible once its commit is recorded in the transaction log
BDelta Lake writes into a temporary table and renames it when the job ends
CDelta Lake locks the table so readers wait until the writer finishes
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.
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?
ABronze
BGold
CSilver
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.