#sql

Explain Streams and Tasks in Snowflake.

Explain Triggers in SQL with examples and scenarios for use.

Explain Union vs Union All in SQL.

Articulate the architectural decisions, scalability trade-offs, and cost implications of designing an AWS data platform. How would you justify glue vs. EMR, Redshift vs. Athena, and when would each choice become cost-prohibitive at scale?

Explain bloom filters in Spark: how they reduce I/O and when they introduce false positives that hurt performance. What are the scalability and cost implications of enabling dynamic partition pruning and bloom filter pushdown at petabyte scale?

Design a star schema for retail analytics (e.g., Adidas). Explain the dimensional modeling choices, SCD strategy, and how you would scale this schema for global multi-currency, multi-region deployments. What are the refresh and storage cost implications?

Explain how to implement cumulative sum in SQL.

Explain normalization in databases and its importance. Write an SQL query to handle SCD-1 or SCD-3