Databricks Certification Practice Test 01
Practice Test 01
Databricks Certification Practice Test 01
Practice Test 01
Insightful Saga — Modern Data Engineering Certification Preparation
Question 1
## Question 1 A data engineer wants to store data in a format that supports ACID transactions, schema enforcement, and time travel. Which storage format should be used?
Delta Lake provides: - ACID transactions - Schema enforcement - Schema evolution - Time Travel - Reliable batch and streaming support CSV, JSON, and Avro do not provide all of these capabilities natively. ---
Question 2
## Question 2 Which component in a Databricks cluster coordinates Spark job execution?
The Driver Node: - Accepts submitted code - Creates execution plans - Coordinates worker nodes - Tracks job progress Worker nodes execute the actual tasks. ---
Question 3
## Question 3 Which architecture layer should contain raw, unmodified source data?
Bronze Layer stores: - Raw source data - Historical records - Minimal transformation Silver is used for cleansing and Gold is used for business-ready reporting. ---
Question 4
## Question 4 A data engineer wants to remove duplicate customer records and standardize column formats. Which layer should perform these operations?
Silver Layer is responsible for: - Data cleansing - Deduplication - Standardization - Data quality improvements ---
Question 5
## Question 5 Which SQL operation should be used to perform inserts and updates in a Delta table?
MERGE supports: - INSERT - UPDATE - DELETE in a single statement and is commonly used for SCD processing. ---
Question 6
## Question 6 A Databricks user needs to review previous versions of a table. Which feature should be used?
Time Travel allows users to query historical versions of Delta tables using a version number or timestamp. ---
Question 7
## Question 7 Which Databricks feature improves query performance by compacting small files?
OPTIMIZE: - Compacts small files - Improves read performance - Reduces file fragmentation ---
Question 8
## Question 8 What is the purpose of the VACUUM command?
VACUUM removes old data files that are no longer referenced by the Delta transaction log. ---
Question 9
## Question 9 A developer wants a query to automatically adapt when data distribution changes during execution. Which feature provides this capability?
Adaptive Query Execution (AQE): - Optimizes joins dynamically - Handles skew automatically - Improves runtime performance ---
Question 10
## Question 10 Which join strategy is most efficient when one table is very small?
Broadcast Join sends the small table to all executors, avoiding large shuffle operations. ---
Question 11
## Question 11 Which command creates a temporary view from a DataFrame?
Temporary views allow SQL queries to run against DataFrames during the current session. ---
Question 12
## Question 12 A company requires centralized access control for catalogs, schemas, and tables. Which Databricks service should be implemented?
Unity Catalog provides: - Centralized governance - Fine-grained permissions - Data lineage - Auditing ---
Question 13
## Question 13 In Unity Catalog hierarchy, which object comes directly below Catalog?
Hierarchy: Catalog → Schema → Table/View ---
Question 14
## Question 14 Which file format is used internally by Delta Lake for data storage?
Delta Lake stores actual data using Parquet files while transaction information is stored in `_delta_log`. ---
Question 15
## Question 15 Which statement best describes schema evolution?
Schema evolution allows adding new columns and adjusting schema without recreating tables. ---
Question 16
## Question 16 What is the main purpose of checkpointing in Structured Streaming?
Checkpointing stores progress information so streaming jobs can recover from failures. ---
Question 17
## Question 17 A nightly ETL process runs only once per day. What is the most cost-effective compute option?
Job Clusters: - Start automatically - Run the job - Terminate automatically This reduces compute costs. ---
Question 18
## Question 18 Which DataFrame operation stores frequently used data in memory?
Caching reduces repeated reads and recomputation of frequently accessed datasets. ---
Question 19
## Question 19 A Delta table contains billions of rows and queries frequently filter by region. Which design choice can improve performance?
Partitioning reduces the amount of data that must be scanned during query execution. ---
Question 20
## Question 20 Which Databricks feature provides a high-performance vectorized query engine?
Photon is Databricks' optimized execution engine designed to improve SQL and DataFrame workload performance. --- title: Databricks Certification Practice Test 02 description: Scenario-Based Certification Questions ---