This article reveals how C++ STL containers like vector, list, map, and unordered_map incur hidden performance costs through memory layout, cache locality, pointer chasing, and rehash overhead, demonstrating that theoretical time complexity often misleads because cache misses dominate real-world performance.
Introduced in C++23, std::flat_map and std::flat_set replace tree‑based maps and sets with vector‑backed, flat containers that offer superior cache locality, faster traversal for small‑to‑medium data sets, and reduced memory overhead, though they incur O(N) insertion costs and iterator invalidation.
This article explains the CPU cache locality principle, shows how to restructure Go data access patterns—including data structures, field ordering, memory allocation, and false sharing avoidance—and demonstrates measurable performance gains with a matrix‑multiplication benchmark.
This article reviews the evolution of modern multi‑core processors and non‑volatile memory, analyzes their impact on database system architecture, discusses cache‑friendly designs, distributed logging, and benchmark results, and highlights the opportunities and challenges for DBMS developers in the era of NVRAM.
