Azure AI Search
One-liner — Microsoft’s managed search-and-vector-index service — the retrieval engine most Azure-based RAG apps (and Azure OpenAI “on your data”) use to find the right chunks to feed an LLM.
What it does — Azure AI Search (formerly Azure Cognitive Search) indexes your content and serves keyword, vector, and hybrid search with semantic ranking. In a RAG pipeline it is the vector-retrieval layer: store embeddings, retrieve top-k relevant chunks at query time. Supports security trimming (filtering results by the caller’s permissions), which is the hook for entitlement-aware retrieval.
Where it sits in the stack — vector-retrieval, retrieval layer (Day-1 if doing RAG). Risk-wise, it holds sensitive data (the indexed corpus + embeddings), so access controls on the index matter. The natural Azure pairing for sharepoint content and microsoft-365-copilot-adjacent custom RAG.
Deployment & architecture — SaaS / managed Azure service, API-driven. Integrates with Azure OpenAI, Microsoft Entra (RBAC), and supports document-level security filters for entitlement-aware results.
Positioning & differentiators — Default for Azure-centric shops; not a pure vector DB but a full search service with vectors added. Neighbors: pinecone (managed pure-play), weaviate (open-source + cloud), opensearch (open-source/self-host).
Ownership, funding & M&A — First-party Microsoft Azure service (public, NASDAQ: MSFT). No M&A. Confidence: high.
CTO / hedge-fund lens — Day-1 RAG infra if you are on Azure — usually you adopt whatever your cloud provides rather than buying a separate vector DB. Verify you wire up security trimming so retrieval honors source permissions.
Competitors / alternatives — pinecone, weaviate, opensearch.
Sources
- [raw/sources/2026-06-28—retrieval-infra—first-party-ownership.md] — supports: Microsoft Azure ownership, rename history; confidence: high
History
- [2026-06-28] Stub created from seed registry.
- [2026-06-28] Researched (light); brief stub — vector retrieval engine. Ownership Microsoft (public, high).