Learning Objectives

By the end of this section, you will be able to:
  • Describe different chunking strategies and when to use them
  • Implement effective document processing techniques
  • Optimize embedding generation and storage
  • Understand performance considerations for RAG systems

Chunking Strategies

Why Chunking Matters

Large documents need to be broken down into smaller pieces for effective embedding and retrieval:

Token Limits

Models have maximum input lengths (e.g., 8K tokens)

Semantic Coherence

Chunks should maintain meaningful context

Retrieval Precision

Smaller chunks allow more precise information retrieval

Processing Efficiency

Smaller chunks are faster to process and embed

Chunking Approaches

function fixedSizeChunk(text: string, chunkSize: number = 1000): string[] {
  const words = text.split(' ');
  const chunks = [];
  
  for (let i = 0; i < words.length; i += chunkSize) {
    chunks.push(words.slice(i, i + chunkSize).join(' '));
  }
  
  return chunks;
}

Chunking Strategy Comparison

Fixed-Size

Pros: Simple, predictable Cons: May break semantic units

Semantic

Pros: Maintains context Cons: Variable chunk sizes

Overlapping

Pros: Preserves context boundaries Cons: More storage, processing overhead

Advanced Chunking Techniques

Hierarchical Chunking

Create chunks at multiple levels (paragraph, section, document)

Metadata-Aware Chunking

Include source, page, and context information with each chunk

Content-Aware Chunking

Adjust chunk size based on content type (code, text, tables)

Dynamic Chunking

Automatically determine optimal chunk size based on content

Performance Considerations

Embedding Generation

Batch Processing

Process multiple chunks together for efficiency

Caching

Cache embeddings to avoid regenerating identical content

Rate Limiting

Respect API rate limits when using external embedding services

Error Handling

Handle API failures and retry with exponential backoff

Best Practices

Chunking Guidelines

1

Analyze Content Structure

Understand your document format and natural break points
2

Choose Appropriate Strategy

Select chunking method based on content type and use case
3

Test and Iterate

Evaluate chunk quality and adjust parameters as needed
4

Monitor Performance

Track processing time and storage requirements

Performance Optimization Tips

Parallel Processing

Use multiple workers for embedding generation

Incremental Updates

Only re-embed changed content

Compression

Compress embeddings for storage efficiency

Caching Strategy

Cache frequently accessed embeddings

Self-Assessment Quiz

Reflection Questions

Extension with AI

Next Steps

You’ve now learned about chunking strategies and performance optimization! In the next module, we’ll start building your RAG chatbot:
  • Setting up the development environment
  • Installing dependencies and tools
  • Understanding the project structure
Key Takeaway: Effective chunking strategies and performance optimization are crucial for building scalable RAG systems that can handle large document collections efficiently.