When Does Adding Fancy RAG Features Work?

Adding complex features like query optimization and context expansion to RAG systems increases cost and latency, raising the question of when these additions are truly beneficial. To find an answer, an experiment compared a basic RAG pipeline against an advanced one using three distinct datasets: clean synthetic questions, messy synthetic questions, and unpredictable real-world queries. The initial results were surprising, showing that for simple, well-formed questions, the advanced features offered no significant advantage over the basic setup. However, the value of these complex features began to emerge when tested against messy and random real-world questions, demonstrating their potential in more challenging, less predictable scenarios.