What does HackerNews think of annoy?

Approximate Nearest Neighbors in C++/Python optimized for memory usage and loading/saving to disk

Language: C++

#22 in C++
#56 in Go
#10 in Lua
#124 in Python
The focus on the top 10 in vector search is a product of wanting to prove value over keyword search. Keyword search is going to miss some conceptual matches. You can try to work around that with tokenization and complex queries with all variations but it's not easy.

Vector search isn't all that new a concept. For example, the annoy library (https://github.com/spotify/annoy) has been around since 2014. It was one of the first open source approximate nearest neighbor libraries. Recommendations have always been a good use case for vector similarity.

Recommendations are a natural extension of search and transformers models made building the vectors for natural language possible. To prove the worth of vector search over keyword search, the focus was always on showing how the top N matches include results not possible with keyword search.

In 2023, there has been a shift towards acknowledging keyword search also has value and that a combination of vector + keyword search (aka hybrid search) operates in the sweet spot. Once again this is validated through the same benchmarks which focus on the top 10.

On top of all this, there is also the reality that the vector database space is very crowded and some want to use their performance benchmarks for marketing.

Disclaimer: I am the author of txtai (https://github.com/neuml/txtai), an open source embeddings database

I like Faiss but I tried Spotify's annoy[1] for a recent project and was pretty impressed.

Since lots of people don't seem to understand how useful these embedding libraries are here's an example. I built a thing that indexes bouldering and climbing competition videos, then builds an embedding of the climber's body position per frame. I then can automatically match different climbers on the same problem.

It works pretty well. Since the body positions are 3D it works reasonably well across camera angles.

The biggest problem is getting the embedding right. I simplified it a lot above because I actually need to embed the problem shape itself because otherwise it matches too well: you get frames of people in identical positions but on different problems!

[1] https://github.com/spotify/annoy

Is your music recommendation system open source? Would be down to check it out and learn a thing or two from it.

On the topic of vector search, I'm fairly certain that Spotify still uses Annoy (https://github.com/spotify/annoy). Like Faiss, it's a great library but not quite a database, which would ideally have features like replication (https://milvus.io/docs/replica.md), caching, and access control, to name a few.