AI engineering glossary · RAG vector search
What is efConstruction?
efConstruction: In HNSW, the size of the candidate list examined while inserting each vector during index building. Higher values produce a better-connected graph and higher recall, but make the build slower.
efConstruction: an example
Setting efConstruction to 200 instead of 100 doubles build time but improves the recall of the finished index.
Related terms
More RAG vector search terms
- efSearch
- Embedding
- Embedding cache
- Embedding drift
- Exact nearest neighbour search
- FAISS
- Faithfulness
- Fixed-size chunking
Where you learn it
efConstruction is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.