Advanced Retrieval Mechanisms in AWS
Explore advanced retrieval mechanisms that improve accuracy and relevance in generative AI systems on AWS. Learn how to combine keyword and vector search, use query expansion and decomposition, apply reranking, and optimize vector database performance with Amazon OpenSearch to build reliable retrieval-augmented generation pipelines.
We'll cover the following...
- Semantic search as the baseline for retrieval
- Advanced retrieval in production RAG systems
- Hybrid search combining keyword and vector retrieval
- Query expansion using FMs
- Query decomposition with Lambda and Step Functions
- Reranking and relevance optimization
- Optimizing vector database performance at scale
- Retrieval mechanism selection by scenario
In real-world generative AI systems, retrieval quality is often the primary factor that determines output reliability. Foundation models rarely fail because they lack language capability. They fail because they are provided with incomplete, noisy, or weakly relevant context. As datasets grow larger and user queries become more complex, basic vector similarity search alone is no longer sufficient to meet accuracy expectations.
This lesson introduces advanced retrieval mechanisms that improve precision and relevance in retrieval augmented generation pipelines. Specifically, this lesson covers the following areas in detail:
Limitations of basic semantic search: Understanding why vector similarity alone can return relevant-sounding but contextually incorrect results in large or heterogeneous datasets.
Hybrid retrieval strategies: Combining keyword-based and vector-based retrieval to balance exact matching with semantic understanding.
Query expansion and decomposition: Improving recall and precision by transforming user queries before retrieval using AWS-native services.
Reranking and relevance optimization: Refines retrieval by ...