Real questions from top companies in SQL
How would you prevent small file problems in S3 when loading data into Redshift?
How would you retrieve the first and last order for each customer from a sales table?
Identify and remove duplicate records from a table, keeping the most recent record based on a timestamp column.
Identify consecutive numbers in a column (at least 3 consecutive).
If manual partitions are created in a Hive data-warehouse table directory, and you query records from those partitions, will you see the data? If not, how can this be fixed?
Implement a CASE WHEN condition - medium difficulty
In Python, process a large CSV in chunks and remove duplicate records based on email and timestamp.
Indexing - True/False question on indexes and query optimization
Kafka Basics - architecture, topics, partitions, producers, consumers, Zookeeper
Kafka Partitioning: How would you ensure even load distribution across Kafka partitions in a high-volume system?
Merge two dictionaries and remove keys with null values.
SQL Query Design: employees with highest salaries within each department
Schema Design: Star vs. Snowflake schema differences
Snowflake Tech Stack: Deployment on Azure, cluster sizing considerations, and overall data warehouse design?
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?
Teradata to Hadoop migration and handling data with SCD Type 2?
Test SQL skills using advanced window functions such as LAG, LEAD, and DENSE_RANK.
Time and cost comparisons for executing the same query in Snowflake and Spark.
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