{"title":"pgvector vs Weaviate","slug":"pgvector-vs-weaviate","tools":[{"name":"pgvector","slug":"pgvector","category":"vectordb","type":"self-hosted","website":"https://github.com/pgvector/pgvector","pricing":"open-source","pricing_tiers":["Free (open-source PostgreSQL extension)","Available on managed Postgres: Supabase, Neon, RDS, Cloud SQL, Crunchy Bridge"],"open_source":true,"self_hosted":true,"sdk_languages":["python","javascript","typescript","go","java","ruby","rust","csharp","php"],"frameworks":["langchain","llamaindex","vercel-ai","haystack"],"agent_features":{"hybrid_search":true,"metadata_filtering":true,"multi_tenancy":false,"managed_embeddings":false,"mcp_server":false,"serverless":false},"compliance":["soc2","hipaa","gdpr","pci-dss"],"best_for":"Teams already running Postgres who want vector search without adding a new database — ACID, joins, and one operational story","limitations":"Slower at scale than purpose-built engines; no native multi-tenancy primitives beyond schemas; hybrid search and serverless depend on the host platform (Supabase, Neon, etc.), not pgvector itself","verified_by":"editorial","last_verified":"2026-06-10","source_urls":{"docs":"https://github.com/pgvector/pgvector#readme","changelog":"https://github.com/pgvector/pgvector/releases","ecosystem":"https://github.com/pgvector/pgvector#hosted-postgres"}},{"name":"Weaviate","slug":"weaviate","category":"vectordb","type":"hybrid","website":"https://weaviate.io","pricing":"freemium","pricing_tiers":["Free (self-hosted, open-source)","Free Hosted","$45/mo Flex","$280/mo Plus","$400/mo Premium"],"open_source":true,"self_hosted":true,"sdk_languages":["python","javascript","typescript","go","java"],"frameworks":["langchain","llamaindex","vercel-ai","haystack","dspy"],"agent_features":{"hybrid_search":true,"metadata_filtering":true,"multi_tenancy":true,"managed_embeddings":true,"mcp_server":true,"serverless":true},"compliance":["soc2","gdpr","hipaa"],"best_for":"Hybrid RAG with built-in vectorizer modules, generative search, and strong multi-tenancy — runs anywhere from laptop to managed cloud","limitations":"Resource-hungry compared to Qdrant or Chroma; module configuration has a learning curve; some advanced replication features are cloud-only","verified_by":"editorial","last_verified":"2026-06-10","source_urls":{"docs":"https://weaviate.io/developers/weaviate","pricing":"https://weaviate.io/pricing","changelog":"https://github.com/weaviate/weaviate/releases"}}],"category":"vectordb","last_verified":"2026-06-10","body":"pgvector adds vectors to Postgres; Weaviate is an AI-native vector database with managed cloud and BYOC options. The decision is whether you want vectors in your existing operational database or in a purpose-built engine with deeper AI tooling.\n\n## Where pgvector wins\n\n* **One database, one backup, one auth story.** ACID transactions span vector and relational writes. Joins enrich vector results in a single query.\n\n* **Row-level security for free multi-tenancy.** Weaviate's tenant-per-collection model is more sophisticated, but pgvector's RLS enforcement is harder to bypass.\n\n* **No new vendor or operational surface.** Postgres is already in most stacks. Weaviate adds a service to run.\n\n## Where Weaviate wins\n\n* **Generative modules run RAG inside the database.** `generative-*` retrieves + calls an LLM in one query. pgvector returns rows; you orchestrate generation in app code.\n\n* **Tenant-per-collection scales to 100k+ tenants with offloading.** First-class per-tenant lifecycle that Postgres schemas don't match.\n\n* **Built-in vectorizer modules.** OpenAI, Cohere, Voyage, Hugging Face, Ollama at ingest time. pgvector stores vectors but generates none.\n\n* **First-party MCP server.** pgvector relies on community wrappers.\n\n## The agentic difference\n\nFor agents that already read and write Postgres data, pgvector keeps everything in one transactional store with RLS-enforced isolation. For agents with many long-tail per-user vector spaces or where you want retrieval + generation inside the database, Weaviate's tenant model and generative modules pull ahead. Weaviate's first-party MCP server simplifies agent integration today.\n\n## When to pick which\n\n* **Pick pgvector** when Postgres is already the operational store and you want vectors inside the same database.\n\n* **Pick Weaviate** when you need first-class multi-tenancy at scale, generative modules, built-in vectorizers, or a first-party MCP server."}