Discussions Reddit Part 2: optimizing the hot path (and finding a weird villain) “Why Objects.equals() showed up in the profile—and why SWAR beat the Vector API on ARM (and x86). In the last post, I finally got a SwissTable-ish map running on the JVM and fast enough to make me smile. Naturally, that meant I immediately started staring at the profiler again, thinking: okay… but how do I make it faster? ...
Discussions Hacker News Reddit One day, I ran into SwissTable—the kind of design that makes you squint, grin, and immediately regret every naive linear-probing table you’ve ever shipped. This post is the story of how I tried to bring that same “why is this so fast?” feeling into Java. It’s part deep dive, part engineering diary, and part cautionary tale about performance work. 1) The SwissTable project, explained the way it feels when you first understand it SwissTable is an open-addressing hash table design that came out of Google’s work and was famously presented as a new C++ hash table approach (and later shipped in Abseil). ...
Swiss Tables:A Modern, High-Performance Hash Table Swiss Table is a high-performance hash table design introduced by Google engineers in 2017. It has since inspired many standard-library implementations across languages, including: Go 1.24 ships its map with this design (up to 60% faster) Rust’s standard HashMap has also moved from Robin Hood hashing to a Swiss Table-inspired layout. Datadog reported as much as 70% memory savings after migrating to Swiss Table Open Addressing, Briefly An open addressing hash table is one of the implementation methods for hash tables. Unlike separate chaining — which uses external data structures such as linked lists or trees — open addressing implements the entire hash table as a single contiguous array. ...