The core idea of the RAG architecture can be summarized as "Retrieve First, Generate Later". The specific process is as follows:
Document Indexing Phase
First, the system needs to preprocess and index knowledge base documents. This includes text chunking, vectorization encoding, and building an efficient vector retrieval index. Common vector databases include ChromaDB, Pinecone, Weaviate, etc., which support fast similarity searches for large-scale documents.
Query Processing Phase
When a user asks a question, the system first converts the query into a vector representation, then retrieves the most relevant document fragments from the vector database. These fragments, along with the original query, are input into the language model.
Generation Enhancement Phase
The language model generates answers based on the retrieved context. Since the model can reference specific external document content, the generated answers are more accurate, traceable, and can effectively avoid information gaps caused by knowledge cutoff.