# RAG Pipelines
RAG Pipelines are the data processing workflows that power [[Retrieval-Augmented Generation (RAG)]] systems. They handle the end-to-end flow from document ingestion to response generation.
## Pipeline Stages
### 1. Ingestion Pipeline
```
Documents → Load → Split → Embed → Store
```
- **Load**: Read documents (PDF, HTML, Markdown, etc.)
- **Split**: Chunk into manageable pieces (by tokens, sentences, or semantics)
- **Embed**: Convert chunks to vectors using embedding models
- **Store**: Index in a [[Vector Store]]
### 2. Query Pipeline
```
Query → Embed → Retrieve → Rerank → Generate
```
- **Embed**: Convert user query to vector
- **Retrieve**: Find similar chunks from vector store
- **Rerank**: Score and filter results for relevance
- **Generate**: Pass context + query to [[Large Language Models (LLMs)|LLM]]
## Pipeline Patterns
| Pattern | Description |
|---------|-------------|
| Naive RAG | Simple retrieve → generate |
| Advanced RAG | Query rewriting, hybrid search, reranking |
| Modular RAG | Component-based architecture enabling flexible composition. Swap retrievers, rerankers, generators independently |
| Agentic RAG | LLM decides what/when to retrieve. The agent drives retrieval decisions rather than following a fixed pipeline |
| Graph-Enhanced RAG | Leverages knowledge graphs for structured relationships between entities, improving reasoning over connected facts |
| Corrective RAG (Self-RAG) | Evaluate retrieval quality, retry if poor. The model critiques its own retrieval before generating |
Notable systems: FlashRAG, GraphRAG, LightRAG, HippoRAG, RAPTOR.
## Key Considerations
- **Chunk size**: Balance context vs precision
- **Overlap**: Prevent splitting important context
- **Embedding model**: Match to your domain
- **Top-k selection**: How many chunks to retrieve
- **Prompt engineering**: How to present retrieved context
## Frameworks
- **[[LangChain]]**: Comprehensive RAG building blocks
- **LlamaIndex**: Specialized for data indexing and RAG
- **Haystack**: End-to-end NLP pipelines
## References
- https://docs.langchain.com/
- https://docs.llamaindex.ai/
## Related
- [[Retrieval-Augmented Generation (RAG)]]
- [[Vector Store]]
- [[LangChain]]
- [[LangGraph]]
- [[Large Language Models (LLMs)]]
- [[AI Agents]]
- [[Embeddings]]
- [[Context Engineering]]