Advanced retrieval on Azure lets AI agents move beyond “good-enough RAG” into precise, context-rich answers by combining hybrid search, graph reasoning, and agentic query planning. This blogpost walks through what that means in practice, using a concrete retail example you can adapt to your own apps.Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptxlearn.microsoft
Why your agents need better retrieval
Most useful agents are really “finders”:
- Shopper agents find products and inventory.
- HR agents find policies and benefits rules.
- Support agents find troubleshooting steps and logs.Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
If retrieval is weak, even the best model hallucinates or returns incomplete answers, which is why Retrieval-Augmented Generation (RAG) became the default pattern for enterprise AI apps.Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
Hybrid search: keywords + vectors + reranking
Different user queries benefit from different retrieval strategies: a precise SKU matches well with keyword search, while fuzzy “garden watering supplies” works better with vectors. Hybrid search runs both in parallel, then fuses them.Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
On Azure, a strong retrieval stack typically includes:learn.microsoft+1Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
- Keyword search using BM25 over an inverted index (great for exact terms and filters).
- Vector search using embeddings with HNSW or DiskANN (great for semantic similarity).
- Reciprocal Rank Fusion (RRF) to merge the two ranked lists into a single result set.
- A semantic or cross-encoder reranker on top to reorder the final set by true relevance.
Example: “garden watering supplies”
Imagine a shopper agent backing a hardware store:
- User asks: “garden watering supplies”.
- Keyword search hits items mentioning “garden”, “hose”, “watering” in name/description.Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
- Vector search finds semantically related items like soaker hoses, planters, and sprinklers, even if the wording differs.Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
- RRF merges both lists so items strong in either keyword or semantic match rise together.learn.microsoftAdvanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
- A reranker model (e.g., Azure AI Search semantic ranker) re-scores top candidates using full text and query context.azure+1Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
This hybrid + reranking stack reliably outperforms pure vector or pure keyword across many query types, especially concept-seeking and long queries.argonsysAdvanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
Going beyond hybrid: graph RAG with PostgreSQL
Some questions are not just “find documents” but “reason over relationships,” such as comparing reviews, features, or compliance constraints. A classic example:Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
“I want a cheap pair of headphones with noise cancellation and great reviews for battery life.”Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
Answering this well requires understanding relationships between:
- Products
- Features (noise cancellation, battery life)
- Review sentiment about those specific features
Building a graph with Apache AGE
Azure Database for PostgreSQL plus Apache AGE turns relational and unstructured data into a queryable property graph, with nodes like Product, Feature, and Review, and edges such as HAS_FEATURE or positive_sentiment.learn.microsoft+1Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
A typical flow in a retail scenario:
- Use
azure_ai.extract()in PostgreSQL to pull product features and sentiments from free-text reviews into structured JSON (e.g., “battery life: positive”).Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx - Load these into an Apache AGE graph so each product connects to features and sentiment-weighted reviews.learn.microsoftAdvanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
- Use Cypher-style queries to answer questions like “headphones where noise cancellation and battery life reviews are mostly positive, sorted by review count.”learn.microsoftAdvanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
Your agent can then:
- Use vector/hybrid search to shortlist candidate products.
- Run a graph query to rank those products by positive feature sentiment.
- Feed only the top graph results into the LLM for grounded, explainable answers.Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
Agentic retrieval with Azure AI Search
Hybrid search and graph RAG still assume a single, well-formed query, but real users often ask multi-part or follow-up questions. Azure AI Search’s agentic retrieval solves this by letting an LLM plan and execute multiple subqueries over your index.securityboulevard+1Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
Example: HR agent multi-part question
Consider an internal HR agent:
“I’m having a baby soon. What’s our parental leave policy, how do I add a baby to benefits, and what’s the open enrollment deadline?”Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
Agentic retrieval pipeline:infoqAdvanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
- Query planning
- Decompose into subqueries: parental leave policy, dependent enrollment steps, open enrollment dates.
- Fix spellings and incorporate chat history (“we talked about my role and region earlier”).
- Fan-out search
- Run parallel searches over policy PDFs, benefits docs, and plan summary pages with hybrid search.
- Results merging and reranking
- Merge results across subqueries, apply rankers, and surface the top snippets from each area.
- LLM synthesis
- LLM draws from all retrieved slices to produce a single, coherent answer, citing relevant docs or links.
Microsoft’s evaluation shows agentic retrieval can materially increase answer quality and coverage for complex, multi-document questions compared to plain RAG.infoqAdvanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
Designing your own advanced retrieval flow
When turning this into a real solution on Azure, a pragmatic pattern looks like this:learn.microsoft+2Advanced-retrieval-for-your-AI-Apps-and-Agents-on-Azure.pptx
- Start with hybrid search + reranking as the default retrieval layer for most agents.
- Introduce graph RAG with Apache AGE when:
- You must reason over relationships (e.g., product–feature–review, user–role–policy).
- You repeatedly join and aggregate across structured entities and unstructured text.
- Add agentic retrieval in Azure AI Search for:
- Multi-part questions.
- Long-running conversations where context and follow-ups matter.
You can mix these strategies: use Azure AI Search’s agentic retrieval to plan and fan out queries, a PostgreSQL + AGE graph to compute relational insights, and then fuse everything back into a single grounded answer stream for your AI app or agent.





