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Database Internals and Scaling
- Authors
- Name
- Lucian Oprea
- @LucianDSA_
00:30:00
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Storage Layout and Access Paths
⏷ 1. How does a database read and write a row on storage?
⏷ 2. How does a B-tree index work, and why is it effective for database queries?
⏷ 3. How should you order columns in a composite index?
⏷ 4. How do LSM trees differ from B-tree-based storage engines?
⏷ 5. Why can adding too many indexes make a database slower?
Query Planning and Execution
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⏷ 6. How does a query planner choose an execution plan?
⏷ 7. How do nested-loop, hash, and merge joins differ?
⏷ 8. When is a full scan better than an index scan?
⏷ 9. Why can the same query become slow even when its SQL has not changed?
Transactions, MVCC, and Recovery
⏷ 10. What does a write-ahead log provide?
⏷ 11. How does MVCC improve concurrency, and what costs does it create?
⏷ 12. Which anomalies do transaction isolation levels prevent?
⏷ 13. How do database locks and deadlocks affect production behavior?
Replication, Sharding, and Rebalancing
⏷ 14. What is the safest order for scaling a database?
⏷ 15. How do synchronous and asynchronous replication affect failover?
⏷ 16. How do you choose a database shard or partition key?
⏷ 17. How can a database rebalance or reshard with minimal downtime?
⏷ 18. What causes hot partitions, and how do you mitigate them?
Model Selection and Performance Decisions
⏷ 19. How do relational, document, key-value, wide-column, graph, and time-series databases differ?
⏷ 20. How would you diagnose and scale a database-backed endpoint that is missing its latency target?
Database Building Blocks
⏷ 21. What is a database page, and why do databases use pages?
⏷ 22. What does a database buffer pool do?
⏷ 23. How do primary and secondary indexes differ?
⏷ 24. What are cardinality and selectivity in an index?
⏷ 25. What happens when a database executes a query?
⏷ 26. Why do applications use database connection pools?
⏷ 27. What are primary and replica database nodes?
Maintenance and Query Patterns
⏷ 28. What do database checkpoints do, and why can they affect latency?
⏷ 29. Why do databases need vacuuming or compaction?
⏷ 30. How do offset and keyset pagination compare?
⏷ 31. How should an application route reads to database replicas?
Safe Growth and Recovery
⏷ 32. How do you perform an online database schema migration?
⏷ 33. How do you handle replication lag without serving incorrect data?
⏷ 34. How would you capacity-plan a growing database?
⏷ 35. How would you design database isolation for a multi-tenant SaaS?