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Home/Questions/SQL/Implement a recursive query for hierarchy (employee-manager). Explain the termination guarantees, depth limits, and when a recursive CTE becomes a scalability bottleneck. What alternatives exist for graph-scale hierarchies in Spark or a data lake?

Implement a recursive query for hierarchy (employee-manager). Explain the termination guarantees, depth limits, and when a recursive CTE becomes a scalability bottleneck. What alternatives exist for graph-scale hierarchies in Spark or a data lake?

SQLmedium0.6 min readPremium
Frequency
Low
Asked at 1 company
Category
487
questions in SQL
Difficulty Split
130E|271M|86H
in this category
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1,863
across 7 categories
Asked at these companies
American Express
Key Concepts Tested
joinspark
Expert AnswerPremium
118 wordsInterview-ready
Implementation: WITH RECURSIVE emp_tree AS (SELECT id, name, manager_id, 1 AS level FROM employees WHERE manager_id IS NULL UNION ALL SELECT e.id, e.name, e.manager_id, t.level + 1 FROM employees e JOIN emp_tree t ON e.manager_id = t.id) SELECT * FROM emp_tree. Why it works: Base case = roots; recursive case = join to prior level. Termination: Ensured by acyclic graph; cycles require cycle detection or LIMIT....
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