Snowflake interview questions

All interview topics

Snowflake interview questions for data engineers and analysts: how the platform works, loading data, performance tuning, data protection, security, sharing and keeping costs under control.

50 questions
12 easy
28 medium
10 hard
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50 of 50 questions

Snowflake interview questions

1What is Snowflake, and how is it different from a traditional data warehouse?EasyBasics

2Describe Snowflake's three-layer architecture.EasyArchitecture

3Why does separating storage and compute matter?EasyArchitecture

4What are micro-partitions?MediumStoragePerformance

5What is partition pruning, and how do you check whether a query benefits from it?MediumPerformance

6What is a clustering key, and when should you define one?HardPerformanceStorage

7What are the Snowflake editions, and what do the higher ones add?EasyBasicsSecurity

8What is a virtual warehouse, and how is it billed?EasyWarehousesCost

9When do you scale a warehouse up, and when do you scale it out?MediumWarehousesPerformance

10What do auto-suspend and auto-resume do, and how would you set them?EasyWarehousesCost

11Explain Snowflake's caching layers.MediumPerformance

12A query that used to take 2 minutes now takes 20. How do you troubleshoot it?HardPerformanceScenario

13What is the Search Optimization Service, and how is it different from clustering?HardPerformance

14What is the Query Acceleration Service?MediumPerformanceWarehouses

15What is Time Travel, and how do you use it?EasyTime TravelData protection

16What is Fail-safe, and how is it different from Time Travel?MediumTime TravelData protection

17What's the difference between permanent, transient and temporary tables?MediumStorageData protection

18How does zero-copy cloning work?MediumCloningStorage

19Someone accidentally dropped a production table. How do you get it back?EasyTime TravelData protection

20What is a stage in Snowflake?EasyLoading

21How does COPY INTO work, and what happens if you run it twice on the same files?MediumLoading

22What is Snowpipe, and when would you use it instead of COPY INTO?MediumLoadingPipelines

23How is Snowpipe Streaming different from Snowpipe?HardLoadingPipelines

24What are best practices for preparing files to load into Snowflake?MediumLoadingPerformance

25How does Snowflake handle JSON and other semi-structured data?MediumSemi-structuredSQL

26How do you turn a JSON array into rows?MediumSemi-structuredSQL

27What is a stream, and how does it track changes?HardPipelinesCDC

28What are tasks, and how do you build a pipeline with streams and tasks?MediumPipelines

29What are dynamic tables, and when would you use them instead of streams and tasks?MediumPipelines

30What are materialized views, and what are their limitations?MediumPerformancePipelines

31How do you upsert data in Snowflake?MediumSQLPipelines

32How does access control work in Snowflake, and what are the system roles?EasySecurityAccess control

33What are best practices for designing roles?MediumSecurityAccess control

34How do you hide sensitive columns or rows from some users?HardSecurityGovernance

35What is a secure view, and when do you need one?MediumSecuritySharing

36How does Snowflake protect data with encryption?MediumSecurity

37How does Secure Data Sharing work?MediumSharing

38How do you protect against a cloud region outage?HardSharingData protection

39What is Snowpark?MediumSnowparkPython

40What's the difference between a UDF and a stored procedure?MediumSQLSnowpark

41What are external tables and Iceberg tables, and when would you use them?HardStorageOpen formats

42What is Snowflake Cortex?EasyAISQL

43How is Snowflake billed?MediumCost

44What is a resource monitor?EasyCostWarehouses

45Your Snowflake bill doubled last month. How do you find the cause and bring it down?HardCostScenario

46What's the difference between ACCOUNT_USAGE and INFORMATION_SCHEMA?MediumOperations

47What does QUALIFY do?MediumSQL

48Does Snowflake enforce primary and foreign keys?MediumSQLData modelling

49How would you build a Type 2 slowly changing dimension in Snowflake?HardData modellingPipelinesScenario

50How do you generate surrogate keys in Snowflake?MediumSQLData modelling