rag-implementation

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# rag-implementation — detailed patterns and worked examples

## Advanced RAG Patterns

### Pattern 1: Hybrid Search with RRF

```python
from langchain_community.retrievers import BM25Retriever
from langchain.retrievers import EnsembleRetriever

# Sparse retriever (BM25 for keyword matching)
bm25_retriever = BM25Retriever.from_documents(documents)
bm25_retriever.k = 10

# Dense retriever (embeddings for semantic search)
dense_retriever = vectorstore.as_retriever(search_kwargs={"k": 10})

# Combine with Reciprocal Rank Fusion weights
ensemble_retriever = EnsembleRetriever(
    retrievers=[bm25_retriever, dense_retriever],
    weights=[0.3, 0.7]  # 30% keyword, 70% semantic
)
```

### Pattern 2: Multi-Query Retrieval

```python
from langchain.retrievers.multi_query import MultiQueryRetriever

# Generate multiple query perspectives for better recall
multi_query_retriever = MultiQueryRetriever.from_llm(
    retriever=vectorstore.as_retriever(search_kwargs={"k": 5}),
    llm=llm
)

# Single query → multiple variations → combined results
results = await multi_query_retriever.ainvoke("What is the main topic?")
```

### Pattern 3: Contextual Compression

```python
from langchain.retrievers

---
name: rag-implementation
description: Build Retrieval-Augmented Generation (RAG) systems for LLM applications with vector databases and semantic search. Use when implementing knowledge-grounded AI, building document Q&A systems, or integrating LLMs with external knowledge bases.
---

# RAG Implementation

Master Retrieval-Augmented Generation (RAG) to build LLM applications that provide accurate, grounded responses using external knowledge sources.

## When to Use This Skill

- Building Q&A systems over proprietary documents
- Creating chatbots with current, factual information
- Implementing semantic search with natural language queries
- Reducing hallucinations with grounded responses
- Enabling LLMs to access domain-specific knowledge
- Building documentation assistants
- Creating research tools with source citation

## Core Components

### 1. Vector Databases

**Purpose**: Store and retrieve document embeddings efficiently

**Options:**

- **Pinecone**: Managed, scalable, serverless
- **Weaviate**: Open-source, hybrid search, GraphQL
- **Milvus**: High performance, on-premise
- **Chroma**: Lightweight, easy to use, local development
- **Qdrant**: Fast, filtered search, Rust