Summary
In this chapter, we covered a wide range of topics related to similarity searching with vectors, a crucial component of RAG systems. We explored the concept of a vector space, discussed the differences between semantic and keyword searches, and covered various distance metrics used to compare the similarity between embeddings, providing code examples to demonstrate their calculation.
We reviewed code that implemented hybrid search using the BM25 algorithm for sparse search and a dense retriever for semantic search, showcasing how to combine and rerank the results. We also discussed semantic search algorithms, focusing on k-NN and ANN, and covered indexing techniques that enhance the efficiency of ANN search, such as LSH, tree-based indexing, PQ, and HNSW.
Finally, we provided an overview of several vector search options available in the market, discussing their key features, strengths, and considerations to help you make an informed decision when selecting a vector search...