BM25 Algorithm for Text Retrieval
Master the BM25 algorithm, the probabilistic ranking function powering Elasticsearch and Lucene for keyword-based document retrieval and search systems.
Explore machine learning concepts related to search. Clear explanations and practical insights.
Master the BM25 algorithm, the probabilistic ranking function powering Elasticsearch and Lucene for keyword-based document retrieval and search systems.
Explore ColBERT and other multi-vector retrieval models that use fine-grained token-level matching for superior search quality.
Build hybrid retrieval systems combining BM25 sparse search with dense vector embeddings using reciprocal rank fusion for superior semantic search performance.
How HNSW, IVF-PQ, and LSH compare for approximate nearest neighbor (ANN) search — recall, latency, memory, build cost, and update characteristics — with Annoy, ScaNN, and DiskANN included for completeness.
Explore how LSH uses probabilistic hash functions to find similar vectors in sub-linear time, perfect for streaming and high-dimensional data.
Learn how IVF-PQ combines clustering and compression to enable billion-scale vector search with minimal memory footprint.
How HNSW navigates a layered proximity graph to find nearest neighbors in logarithmic time — the default in-memory index of modern vector databases.