RAG

Retrieval changes what a model can see; fine-tuning changes how it answers. A diagnostic for telling which problem you have, and the arithmetic for deciding when a lexical index is worth adding.

• RAG ·
• LLMs

Corpus size decides between retrieval and a long context window. Fine-tuning sits on another axis. The crossover is derived twice; the fine-tune never pays.

• RAG ·
• LLMs ·
• Cost

Why a semantic cache breaks even at a 0.01 per cent repeat rate, how to set the threshold from a false-hit budget, and what the semantic half is worth.

• Caching ·
• Cost ·
• RAG

Why the splitter loses the number and the model never had it: split probability derived at LlamaIndex’s shipped defaults, compounded across a 1,200-table corpus, and what a bigger chunk costs.

• RAG ·
• LLMs