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Sep 16, 2026 · Databases

How LSM Tree Overturned B-Tree: The 1996 Innovation Behind Modern Write-Heavy Databases

This article traces the origin of the Log-Structured Merge-Tree (LSM Tree) from a 1996 paper by Patrick O'Neil et al., explaining how its sequential-write, background-compaction design solved the random I/O bottleneck of B-Trees, enabling modern write-heavy systems like Cassandra, RocksDB, and Kafka.