Developer Interview Questions at Cognizant
5 real Developer interview questions asked at Cognizant. Covers Technical rounds. Sourced from engineers who cleared the loop.
Interview Signals — What Cognizant Asks Developers
All Developer Questions Asked at Cognizant
Write a query to find, for each department, the employee with the second-highest salary, using window functions instead of a correlated subquery.
Explain the difference between INNER JOIN, LEFT JOIN, and FULL OUTER JOIN with a simple example of Orders and Customers tables.
A SELECT query filtering on a non-indexed column takes 8 seconds on a 10 million row table. Would adding an index always help? What's the trade-off of adding too many indexes?
What problem does database normalization (1NF, 2NF, 3NF) actually solve? Give an example of an update anomaly in an unnormalized table.
How would you find out why a specific SQL query is slow before making any changes to it?
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