Semantic Search vs. Full-Text Search: Which Do I Choose in Milvus 2.5?

This post details the integration of full-text search (FTS) with semantic search in Milvus 2.5, enabling hybrid search capabilities. It explains the use of BM25 for lexical matching and Reciprocal Rank Fusion (RRF) for merging and ranking results from both semantic (dense embeddings) and full-text search paths. The post provides a practical example using Anthropic's code snippet dataset to demonstrate how hybrid search outperforms individual semantic or full-text search, particularly in scenarios requiring keyword matching. It analyzes specific cases and presents Pass@5 metrics to quantify the improvements, highlighting the value of combining keyword relevance with semantic understanding for AI-assisted coding bots and similar RAG applications.