Log Structured Merge Tree

Definitions

1. A write-optimized data structure (LSM-tree) that buffers writes in an in-memory sorted structure (memtable) and periodically flushes them to immutable sorted files (SSTables) on disk, which are later merged via background compaction. Used by LevelDB, RocksDB, Cassandra, and ScyllaDB to achieve high write throughput at the cost of read amplification.

   In plain English: A storage design that makes writing data extremely fast by first collecting writes in memory and then sorting and merging them to disk in the background.

   Example: "We chose RocksDB's LSM-tree engine for the time-series data because it handles our 500K writes per second without breaking a sweat."

Related Terms

• WAL
• MVCC
• MEV
• APL
• Monomorphization
• Read-Copy-Update
• Reader Monad
• RocksDB