

Simple query in ChatGPT produced 

Metric | Best For | Type | Notes
-- | -- | -- | --
Cosine Similarity | L2-normalized vectors | Similarity | Scale-invariant
Dot Product | Transformer embeddings | Similarity | Fast, especially on GPUs
Euclidean Distance | Raw vectors with meaningful norms | Distance | Sensitive to scale
Jaccard | Sparse binary or set-based data | Similarity | Discrete features
Soft Cosine | Sparse with semantic overlap | Similarity | Better for text-term overlap
Learned Similarity | Fine-tuned deep models | Varies | Best accuracy, slowest retrieval

