schema · growing
Small-to-big retrieval
Embed the small thing, hand the big thing to the answer. Sentence window, parent/child, references.
Intuition: embedding a big block of text is a bad idea. The vector blurs and the one sentence the question asks about drowns in noise.
The fix: embed the small thing, hand the big thing to the answer.
Embed sentence
Match
Expand window k=2
Wide context to LLM
Embed child chunk
Match
Fetch parent chunk
Synthesise from parent
Embed summary/metadata
Match
Fetch the original
Synthesise from original
The measured difference
| Retriever | hit rate | MRR |
|---|---|---|
| Base (plain chunk) | 0.796 | 0.605 |
| Chunk references | 0.892 | 0.740 |
| Metadata references | 0.916 | 0.747 |
Source: LlamaIndex advanced-retrieval benchmarks. The absolute numbers move with the corpus; the ordering usually holds.