Every high-throughput database, cache tier, and stream processor is built upon a small set of specialized data structures designed around the physical asymmetry between CPU cache lines, DRAM, and NVMe flash pages. Choosing between a Tree and an LSM-Tree, or between an R-Tree and a discrete H3 hexagonal grid, directly dictates a storage engine’s read amplification, write amplification, and space amplification.
This chapter progresses systematically from disk-backed indexing to probabilistic memory structures. You first dissect 16 KB slotted-page Trees and two-dimensional spatial indexes (CORE-M08-004), then contrast their in-place random write amplification against append-only LSM-Trees and SSTable compaction (CORE-M08-003). Next, you eliminate SSTable point-lookup I/O waste using Bloom and Cuckoo Filters (CORE-M08-001), distribute keys across cluster nodes via Consistent Hashing with Virtual Nodes (CORE-M08-002), and bound high-cardinality streaming telemetry in kilobytes of RAM using HyperLogLog and Count-Min Sketch (CORE-M08-005).