RAG Explained: How Retrieval-Augmented Generation Actually Works
Understand the architecture behind RAG systems — the technology that lets AI answer questions about your specific data.
Retrieval-Augmented Generation (RAG) is the technique that makes AI useful for your specific data. Instead of relying solely on the model's training data, RAG retrieves relevant documents and uses them as context.
The RAG Pipeline
Step 1: Document Ingestion
First, your documents are split into chunks and converted to vector embeddings:
python1
splitter = RecursiveCharacterTextSplitter( chunk_size=1000, chunk_overlap=200 ) chunks = splitter.split_documents(documents) ```
Step 2: Vector Storage
Store embeddings in a vector database for fast similarity search:
python1
vectorstore = Chroma.from_documents( documents=chunks, embedding=OpenAIEmbeddings() ) ```
Step 3: Retrieval & Generation
When a user asks a question, retrieve relevant chunks and pass them to the LLM:
python1retriever = vectorstore.as_retriever(search_kwargs={"k": 5})2relevant_docs = retriever.get_relevant_documents(query)
Key Decisions
| Decision | Options | Tradeoff |
|---|---|---|
| Chunk size | 200-2000 tokens | Precision vs context |
| Overlap | 10-20% | Recall vs storage |
| Top-K | 3-10 documents | Context quality vs length |
When to Use RAG
- Internal documentation Q&A
- Customer support with knowledge base
- Research over large document collections
- Any task requiring specific, up-to-date information