Databricks
15 questionsDelta Lake, Unity Catalog, workflows, and performance optimization. Essential Databricks knowledge for lakehouse interviews.
Delta Lake ACID Transactions
What is Delta Lake and how does it provide ACID transactions on top of a data lake?
Delta Lake MERGE/UPSERT
How do you perform an upsert (MERGE) operation in Delta Lake? Give a practical example.
OPTIMIZE, ZORDER, and VACUUM
Explain OPTIMIZE, ZORDER, and VACUUM in Delta Lake. How do they relate to each other?
Delta Lake vs Iceberg vs Hudi
Compare Delta Lake, Apache Iceberg, and Apache Hudi. When would you choose each?
Liquid Clustering
What is liquid clustering in Delta Lake and how does it improve on traditional partitioning + ZORDER?
Change Data Feed
What is Delta Lake's Change Data Feed (CDF)? How does it differ from Spark Structured Streaming on Delta?
Unity Catalog: Three-Level Namespace
What is Unity Catalog and how does its three-level namespace work?
Unity Catalog Permissions Model
Explain Unity Catalog's permissions model. How do you implement fine-grained access control?
Databricks Workflows vs Airflow
Compare Databricks Workflows with Apache Airflow for orchestrating data pipelines. When would you use each?
Job Clusters vs All-Purpose Clusters
What's the difference between job clusters and all-purpose clusters in Databricks? How does this affect cost?
Photon Engine
What is the Photon engine in Databricks? When does it provide the biggest performance gains?
Delta Live Tables (DLT)
What are Delta Live Tables? How do expectations work for data quality?
Medallion Architecture on Databricks
Explain the medallion (bronze/silver/gold) architecture. How do you implement it on Databricks?
Databricks SQL Warehouses
What are Databricks SQL Warehouses? How do they compare to interactive clusters for BI workloads?
Databricks vs EMR Cost Comparison
Your team is debating Databricks vs EMR for Spark workloads. How do you evaluate the cost and performance tradeoffs?