Modern AI agents need three different kinds of memory and only one of them is RAG. The episodic, relational, time-anchored kind needs a graph — and pg-raggraph happens to be shaped exactly right. Tier 1 evolution awareness, retraction-aware retrieval, namespace isolation. What’s built, what’s still gap.
A 17× perf gap between pg-raggraph and Apache AGE turned out to be 5 lines of glue code in the bakeoff adapter, not an architectural problem. The fix, the four library-side wins still on the floor, and the three architectural directions ahead — pg_net sidecar, pgrx Rust extension, hybrid embedding tiers.
Three corpora, three different winners, none of them the chunker the README recommended. Why nobody can tell you in advance which chunker to use, and the 30-minute primitive that does the work for you.
AGE is a property-graph engine; pg-raggraph is read-mostly retrieval that combines vector + BM25 + shallow graph traversal in one query plan. Where each wins, where neither fits, and the deployment story that closes off most of the postgres install base.
Most teams reach for Neo4j or Apache AGE the moment they read the Microsoft GraphRAG paper. The honest answer is most GraphRAG workloads don’t need a graph database — pgvector + recursive CTEs + tsvector handle 1-3 hop traversal in one ACID database.
