Real questions from top companies in SQL · easy
Explain the differences between a Data Lake and a Data Warehouse.
Explain the concept of ACID properties in the context of databases.
Explain Common Table Expressions (CTEs) and their benefits.
Explain the difference between UNION and UNION ALL.
What is the difference between a clustered and non-clustered index?
What is the difference between DELETE and TRUNCATE?
What is a CTE (Common Table Expression)? What are its uses?
Are you comfortable with the variable pay structure, and what are your expectations for the base salary?
CSV Without Column Names/Schema - how to read
Compare Redshift, BigQuery, and Snowflake in terms of cost, performance, and scalability.
Converting SCD0 to SCD3
Describe a cross-team data project where you had to align architectural boundaries, ownership, and SLAs. How did you handle conflicting priorities, technical debt, and the scalability of communication as the number of stakeholders grew?
Walk through a production incident where data freshness or correctness was at risk. How did you balance immediate mitigation vs. root-cause remediation? What architectural changes would prevent recurrence, and what are the cost vs. reliability trade-offs?
How would you handle null values in a dataset, especially in a single column?
Identify consecutive numbers in a column (at least 3 consecutive).
Merge two dictionaries and remove keys with null values.
Strategies for working with busy team leads?
Tasks where the candidate faced failure and lessons learned.
Tell us about a project where you optimized an existing process or pipeline. What was the impact?
Use cases for internal staging in Snowflake?
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