Real questions from top companies · medium
Normalization: Concepts and its importance
Normalization: Various forms and impact on query performance
Number of Rows in Different Joins
Oozie join condition?
Optimize SQL using indexing and partitioning filters.
Optimize a query fetching customer data with a rolling 6-month sales sum.
Optimize a slow SQL query for a large orders table containing billions of rows.
Optimizing Spark Jobs when they take longer than expected
PIVOT Operator in T-SQL
Partitioning a table with card details and transactions?
Predict the output of SQL joins (INNER, LEFT, RIGHT) on dataset containing 0, NULL, and 1
Predicted outputs for different join types using two sample tables with NULL values.
Print only the newest record for each name – Use SQL Window functions (ROW_NUMBER, RANK, etc.)
Query for 2nd Latest Joining Per Department
Query to Print Match List Against Every Team
REPARTITION vs COALESCE for managing partitions
Rank, Dense Rank, and Row Number - Differences
Removing duplicates - ROW_NUMBER() or DISTINCT
SELF JOIN Applications - scenarios like manager-employee relationships
SQL Case study involving bank liabilities, loans, and balances - extensive JOINs and CASE statements
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