Vector Database Architecture Comparison
Choosing a vector store means trading off control, convenience, and features. This diagram lays out three popular solutions - FAISS, Pinecone, and Weaviate - as layered architecture stacks, from the application down to the deployment model, followed by a feature comparison matrix.
Interactive Demo
Hover over any layer to read what that part of the stack does.
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Overview
Each column is an architecture stack read from top (your application) to bottom (how it is deployed). FAISS is an embedded library you compile into your own program; Pinecone is a fully managed cloud service behind an API; Weaviate is an open-source engine you can self-host or run in the cloud, with hybrid search built in.
How It Works
- FAISS (blue) - a high-performance library. You call index APIs directly and manage persistence, scaling, and metadata yourself. Native GPU support.
- Pinecone (green) - a serverless managed service. You talk to a REST/gRPC API and Pinecone auto-scales storage; no infrastructure to run, cloud-only.
- Weaviate (purple) - an open-source database with a schema, vectorization modules, and an HNSW + BM25 index enabling hybrid keyword-plus-vector search.
Feature Comparison
| Feature | FAISS | Pinecone | Weaviate |
|---|---|---|---|
| Deployment | Embedded library | Fully managed cloud | Self-hosted or cloud |
| Pricing | Free (open-source) | Usage-based | Free (OSS) or managed |
| Metadata | Manual | Built-in | Built-in with schema |
| Hybrid search | No | Limited | Yes (BM25 + vector) |
| GPU support | Yes (native) | No (abstracted) | No (CPU optimized) |
| Scalability | Manual sharding | Automatic | Manual or managed |
| Best for | Maximum control | Fast deployment | Hybrid search needs |
Lesson Plan
- Warm up: Ask what "vector database" responsibilities a team takes on when they embed a library versus when they call a managed API.
- Explore: Hover each layer in all three columns and identify which layers are shared (gray) versus product-specific.
- Discuss: When is FAISS's manual control worth the extra engineering? When does Weaviate's hybrid search justify self-hosting?
- Extend: Have students pick a solution for a startup with no ops team versus a research lab with GPUs, and defend each choice with the matrix.