AWS published a comparison guide for choosing a vector store in Amazon Bedrock Knowledge Bases across OpenSearch, Aurora PostgreSQL with pgvector, and S3 Vectors, pairing benchmarks with a decision framework tied to RAG use case rather than data size alone.

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Amazon Bedrock: How to Choose the Right Vector Store for RAG

What AWS published

FAQ

What is a vector store in Amazon Bedrock Knowledge Bases?

It is the component that stores and indexes document embeddings so a RAG application can retrieve the most relevant chunks before passing them to the language model. Bedrock supports options including OpenSearch, Aurora PostgreSQL with pgvector, and S3 Vectors.

How do OpenSearch, Aurora pgvector, and S3 Vectors differ?

OpenSearch is a search engine tuned for hybrid search, filtering, and concurrent queries. Aurora PostgreSQL with pgvector keeps vectors alongside relational data in one database, reducing system count. S3 Vectors lowers cost at scale but is less suited to low-latency concurrent queries.

Should MENA teams act on this comparison now?

Yes, especially teams building internal assistants or knowledge search on AWS. Picking the wrong vector store early leads to costly re-engineering later, and the framework reduces that risk.

What is the most important selection criterion?

Query pattern comes first: do you need hybrid search with complex filters, integration with relational data, or large-scale low-frequency retrieval? Then consider data volume, required latency, and cost.

Source: AWS Machine Learning

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