FTS

Full-text search over string fields (tokenizers such as Jieba where configured upstream).

When to use

• Keyword / lexical retrieval alongside dense vectors
• Hybrid RAG patterns (dense + FTS fusion)

ZVec.NET mapping

Concern	Type / API
Index params	ZVecFtsIndexParam
Query	ZVecFtsQuery on ZVecQuery.Fts
Fusion	Combine with vector sub-queries + RRF / weighted

Pitfalls

• Embeddings and chat models are host/sample concerns — not part of the NuGet DB SDK
• Tokenizer/language behavior is defined by upstream ZVec

Upstream

• zvec.org
• .NET hybrid guide