🗄️ Vector Databases 🗄️ 向量数据库

Best Vector Databases in 2026
(Open Source, Ranked by GitHub Stars)
2026 年最佳向量数据库
(开源,按 GitHub Stars 排序)

A vector database is a specialized storage system designed to efficiently index and query high-dimensional embeddings — the numerical representations that make AI search, RAG pipelines, and semantic similarity possible at scale. As retrieval-augmented generation (RAG) has become the dominant pattern for grounding LLM responses in real data, choosing the right vector database has become a critical architectural decision. This guide compares the top open source vector databases by GitHub stars, query performance, and real-world use cases. 向量数据库是专门设计用于高效索引和查询高维嵌入向量的存储系统——这些数值表示使得大规模 AI 搜索、RAG 流水线和语义相似性成为可能。随着检索增强生成(RAG)成为将 LLM 响应锚定于真实数据的主流模式,选择合适的向量数据库已成为关键架构决策。本指南按 GitHub Stars、查询性能和实际使用场景对主流开源向量数据库进行横向对比。

8
Databases Listed
44K+
Top Stars (Milvus)
6/8
Support Cloud + Self-host
Jun 2026
Data Updated

Vector Database Comparison (Ranked by GitHub Stars) 向量数据库对比(按 GitHub Stars 排序)

The following table ranks 8 major open source vector databases by GitHub stars as of June 2026. All listed databases are open source with self-hosting options; several also offer managed cloud services.

下表按 2026 年 6 月的 GitHub Stars 数对 8 个主流开源向量数据库进行排名,所有列出的数据库均为开源并支持自托管,部分还提供托管云服务。

# Database GitHub Stars Best For Cloud / Self-host License
1 Milvus 44,567 Large-scale production with billions of vectors Both Apache-2.0
2 Faiss 40,175 Research and batch similarity search Self-host only MIT
3 Qdrant 31,717 High-performance filtering + hybrid search Both Apache-2.0
4 Chroma 28,163 Local development and LangChain integration Both Apache-2.0
5 pgvector 21,548 Adding vector search to existing PostgreSQL Self-host PostgreSQL
6 txtai 12,622 All-in-one embeddings + search pipeline Self-host Apache-2.0
7 Weaviate 16,258 Semantic search with built-in ML models Both BSD-3
8 LanceDB 10,463 Serverless, embedded vector DB for apps Both Apache-2.0

Which Vector Database Should You Choose? 如何选择适合你的向量数据库?

The right vector database depends on your development stage, dataset scale, infrastructure preferences, and query requirements. Here's a scenario-based decision guide.

选择合适的向量数据库取决于你的开发阶段、数据集规模、基础设施偏好和查询需求。以下是基于场景的决策指南。

🚀 Scenario
Local development & prototyping
Use Chroma. It's the easiest to get started with — runs in-memory or on disk with a single Python import, has native LangChain and LlamaIndex integrations, and requires zero configuration. Perfect for building RAG prototypes before choosing a production database.
🐘 Scenario
Already running PostgreSQL
Use pgvector. If your application already uses PostgreSQL, pgvector adds vector search as a native extension with standard SQL syntax — no additional infrastructure, ACID transactions, and the ability to combine vector search with SQL filters in a single query. Works great for datasets under ~5 million vectors.
⚡ Scenario
Production high-performance RAG
Use Qdrant or Milvus. Qdrant (Rust-based) excels at high-throughput filtered search and hybrid dense+sparse retrieval — ideal for most production RAG applications. Milvus handles billion-vector scale with distributed architecture. Both offer managed cloud services.
🔍 Scenario
Semantic search with built-in ML
Use Weaviate. It has built-in support for running embedding models directly within the database, supports multimodal search (text + images), and has a GraphQL API with powerful cross-reference querying. Good fit for search applications where you want the DB to handle embeddings.
☁️ Scenario
Serverless / embedded in application
Use LanceDB. It's designed as an embedded or serverless vector database — stores data in columnar Lance format on local disk or S3/GCS, with zero server process. Works well for edge deployments, serverless functions, or apps where you don't want to manage a separate DB service.
🔬 Scenario
ML research & offline batch search
Use Faiss. Meta's highly optimized C++ library is the gold standard for offline similarity search experiments. It supports GPU acceleration for massive speedups and offers a wide variety of index types (IVF, HNSW, PQ) for trading off accuracy vs speed. Not a full database — just a search library.

In 2026, the vector database decision has become clearer: Chroma for prototyping, pgvector if you're Postgres-native, and Qdrant for production RAG at serious scale. Milvus remains the choice when you have genuine billion-vector requirements. The interesting emerging pattern is "hybrid search" — combining dense vector search with sparse BM25 keyword search — which Qdrant and Weaviate handle best. Pure dense vector search alone often underperforms when users include specific named entities or product codes in their queries, which sparse retrieval handles better.

2026 年,向量数据库的选型决策已越来越清晰:原型阶段用 Chroma,Postgres 用户用 pgvector,生产规模 RAG 用 Qdrant。Milvus 是真正需要亿级向量规模时的选择。正在涌现的有趣模式是"混合搜索"——将密集向量搜索与稀疏 BM25 关键词搜索结合——Qdrant 和 Weaviate 在这方面表现最好。单纯的密集向量搜索在用户查询中包含特定命名实体或产品编号时往往表现欠佳,而稀疏检索则能更好处理这类情况。

— AI Nav Editorial Team, June 2026

Database Deep Dives 数据库详细解析

Milvus — Enterprise-Grade at Billion-Vector Scale

Milvus is a cloud-native, distributed vector database purpose-built for production scale. Its architecture separates storage, compute, and coordination into independent microservices, enabling horizontal scaling of each component independently. Milvus supports GPU acceleration, multiple index types (FLAT, IVF_FLAT, HNSW, DiskANN), and can handle tens of billions of vectors with sub-millisecond query latency. The managed cloud version is Zilliz Cloud. If you're building a large-scale recommendation system, image similarity search, or enterprise knowledge base, Milvus is the most battle-tested option.

Milvus 是一个云原生分布式向量数据库,专为生产规模而生。其架构将存储、计算和协调分离为独立的微服务,可对每个组件独立进行水平扩展。Milvus 支持 GPU 加速、多种索引类型(FLAT、IVF_FLAT、HNSW、DiskANN),能以毫秒以下的查询延迟处理数百亿向量。托管云版本为 Zilliz Cloud。如果你在构建大规模推荐系统、图像相似性搜索或企业知识库,Milvus 是经过最充分验证的选择。

Qdrant — The Production RAG Champion

Qdrant is written in Rust, which gives it exceptional memory efficiency and query throughput compared to Python or Java-based alternatives. Its standout features are: sparse+dense hybrid search with Reciprocal Rank Fusion (RRF), rich payload metadata filtering evaluated server-side before vector operations, on-disk HNSW indexing for datasets larger than RAM, and a clean REST+gRPC API. Qdrant Cloud offers a generous free tier (1GB) and transparent per-GB pricing. For most developers building production RAG applications in 2026, Qdrant has become the default choice.

Qdrant 使用 Rust 编写,相比 Python 或 Java 的竞品具有卓越的内存效率和查询吞吐量。其突出特性包括:稀疏+密集混合搜索(RRF 融合)、在向量操作前服务端侧评估的丰富元数据过滤、用于超出内存数据集的磁盘 HNSW 索引,以及简洁的 REST+gRPC API。Qdrant Cloud 提供慷慨的免费套餐(1GB)和透明的按 GB 计费。对于 2026 年构建生产 RAG 应用的大多数开发者,Qdrant 已成为默认选择。

Chroma — The Developer-Friendly Starting Point

Chroma optimizes for developer experience above all else. It runs as an in-process Python library (no server needed) or as a lightweight server, persists to disk with a single line of code, and integrates natively with LangChain, LlamaIndex, and most other Python AI frameworks. Chroma handles the embedding model management for you if desired. For local development, RAG prototyping, and applications handling up to a few million vectors, Chroma's simplicity is genuinely unmatched. Chroma Cloud (managed service) launched in 2025 for teams that want production Chroma without self-hosting.

Chroma 最优先考虑开发者体验。它可以作为进程内 Python 库(无需服务器)或轻量级服务器运行,用一行代码持久化到磁盘,并与 LangChain、LlamaIndex 及大多数 Python AI 框架原生集成。如有需要,Chroma 还可以为你管理嵌入模型。对于本地开发、RAG 原型以及处理数百万向量以内的应用,Chroma 的简便性确实无与伦比。Chroma Cloud(托管服务)于 2025 年面向不想自托管的团队推出。

pgvector — SQL Vector Search for Postgres Users

pgvector adds vector similarity search to PostgreSQL as a native extension. It supports L2 distance, inner product, and cosine distance operators, HNSW and IVFFlat indexing methods, and can store vectors alongside regular Postgres columns in the same table. The key advantage is architectural simplicity: you query vectors with SQL, get ACID transactions, use your existing Postgres tooling (backups, replication, ORMs), and don't need to maintain a second database. Major cloud providers (AWS RDS, Supabase, Neon, Google AlloyDB) support pgvector natively. Performance is sufficient for most applications — limitations only appear at very high query volume or extreme scale.

pgvector 以原生扩展的形式为 PostgreSQL 添加向量相似性搜索。支持 L2 距离、内积和余弦距离算子,HNSW 和 IVFFlat 索引方法,可在同一张表中将向量与普通 Postgres 列一起存储。关键优势在于架构简洁性:你用 SQL 查询向量,获得 ACID 事务,使用现有的 Postgres 工具链(备份、复制、ORM),无需维护第二个数据库。主要云服务商(AWS RDS、Supabase、Neon、Google AlloyDB)均原生支持 pgvector。对大多数应用性能已足够——局限性只在极高查询量或极端规模时才会显现。

Quick Start: Build a RAG Pipeline with Chroma + LangChain 快速上手:用 Chroma + LangChain 构建 RAG 流水线

Here's a minimal working RAG pipeline using Chroma as the vector store and LangChain for orchestration:

以下是使用 Chroma 作为向量存储、LangChain 进行编排的最简可用 RAG 流水线:

# 安装依赖
pip install langchain langchain-openai langchain-chroma chromadb

from langchain_openai import OpenAIEmbeddings, ChatOpenAI
from langchain_chroma import Chroma
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain.chains import RetrievalQA

# 准备文档
documents = [
    "Qdrant is a vector database written in Rust, optimized for high-performance filtering.",
    "Milvus is a cloud-native distributed vector database for billion-scale deployments.",
    "Chroma is designed for developer simplicity and LangChain integration.",
    "pgvector adds vector search to PostgreSQL as a native extension.",
]

# 切分文档
splitter = RecursiveCharacterTextSplitter(chunk_size=200, chunk_overlap=20)
chunks = splitter.create_documents(documents)

# 创建向量存储(自动嵌入并存储)
embeddings = OpenAIEmbeddings()
vectorstore = Chroma.from_documents(
    documents=chunks,
    embedding=embeddings,
    persist_directory="./chroma_db"  # 持久化到磁盘
)

# 创建 RAG 检索链
retriever = vectorstore.as_retriever(search_kwargs={"k": 3})
llm = ChatOpenAI(model="gpt-4o-mini")

qa_chain = RetrievalQA.from_chain_type(
    llm=llm,
    retriever=retriever,
    return_source_documents=True
)

# 提问
result = qa_chain.invoke("Which vector database is best for high-performance filtering?")
print(result["result"])

To switch from Chroma to Qdrant in production, simply replace the vector store initialization:

在生产环境中从 Chroma 切换到 Qdrant,只需替换向量存储初始化部分:

# 安装 Qdrant 客户端
pip install langchain-qdrant qdrant-client

from langchain_qdrant import Qdrant
from qdrant_client import QdrantClient

# 连接本地 Qdrant(先 docker run -p 6333:6333 qdrant/qdrant)
client = QdrantClient(host="localhost", port=6333)

vectorstore = Qdrant.from_documents(
    documents=chunks,
    embedding=embeddings,
    url="http://localhost:6333",
    collection_name="my_rag_docs",
)

# 其余代码完全相同 — LangChain 接口统一
retriever = vectorstore.as_retriever(search_kwargs={"k": 3})

Performance at a Glance 性能速览

This is a high-level comparison based on public benchmarks and community reports. Actual performance varies heavily by dataset size, query complexity, hardware, and configuration.

以下是基于公开基准测试和社区报告的高层对比,实际性能因数据集大小、查询复杂度、硬件和配置不同而差异显著。

Qdrant
Query SpeedExcellent
FilteringBest-in-class
SetupEasy
Scale Limit~Billions
Milvus
Query SpeedExcellent
FilteringGood
SetupComplex
Scale LimitBillions+
Chroma
Query SpeedGood
FilteringBasic
SetupTrivial
Scale Limit~Millions
pgvector
Query SpeedModerate
FilteringFull SQL
SetupZero (Postgres)
Scale Limit~10M rows
Weaviate
Query SpeedGood
FilteringGood
SetupEasy
Scale Limit~Billions
LanceDB
Query SpeedGood
FilteringGood
SetupEmbedded
Scale Limit~Billions

Frequently Asked Questions 常见问题解答

What is a vector database and why do I need one for AI?
A vector database is a specialized database designed to store, index, and query high-dimensional vector embeddings — the numerical representations that AI models use to encode semantic meaning. When you build a RAG (Retrieval-Augmented Generation) system, your documents are chunked, converted into vectors by an embedding model (like OpenAI's text-embedding-3, Cohere's embed-v3, or a local model via Ollama), and stored in the vector database. At query time, your question is also converted to a vector, and the database performs approximate nearest neighbor (ANN) search to find the most semantically similar documents. Traditional SQL databases can do exact k-nearest neighbor search, but they can't do it efficiently at scale — a dedicated vector database can query millions of vectors in under 10ms.
Chroma vs Qdrant — which vector database is better for RAG?
For local development and prototyping, Chroma is the better choice: it requires zero configuration, runs in-memory or on disk, has excellent LangChain integration, and can be started with just three lines of Python. For production RAG systems, Qdrant is generally superior: it supports advanced filtering on metadata fields (evaluated server-side before vector operations, which is crucial for performance), sparse+dense hybrid search for better retrieval quality, on-disk indexing for large datasets, and has a Rust-based engine that delivers excellent throughput. Most developers start with Chroma and migrate to Qdrant when they need production-grade performance and filtering capabilities.
What is the fastest open source vector database?
For raw similarity search speed as a library (not a full database), Faiss (from Meta AI) is typically the fastest — it's a highly optimized C++ library with GPU support. For a full production database with filtering, network API, persistence, and durability, Qdrant consistently scores at the top of ann-benchmarks.com performance tests due to its Rust implementation and HNSW optimization. Milvus is optimized for distributed deployments at billion-vector scale with dedicated query nodes. The "fastest" depends heavily on: dataset size (millions vs billions), whether you need metadata filtering, hardware (CPU vs GPU), query concurrency, and recall-vs-speed trade-offs configured at index build time.
Can I use pgvector instead of a dedicated vector database?
Yes, for many use cases pgvector is an excellent choice — especially if you're already running PostgreSQL. It adds vector similarity search as a native extension with standard SQL syntax and supports HNSW and IVFFlat indexing. For datasets under roughly 5-10 million vectors with moderate query throughput (under a few thousand queries per second), pgvector performance is typically sufficient. The key advantages: zero additional infrastructure (use your existing Postgres instance), full ACID transactions combining vector + SQL queries, and compatibility with the entire PostgreSQL ecosystem (pgAdmin, Supabase, Hasura, ORMs). The limitations: at very high QPS or billion-vector scale, dedicated vector databases like Qdrant or Milvus will significantly outperform pgvector.
Which vector database works best with LangChain?
LangChain has first-class built-in integrations for all major vector databases via the langchain-community and database-specific packages (langchain-chroma, langchain-qdrant, etc.). They all implement the same VectorStore interface, so switching between them requires minimal code changes. Chroma is historically the default in LangChain tutorials because it requires zero setup — just pip install chromadb. In practice, the most common production pattern among LangChain users is: Chroma for local development, then Qdrant or Milvus for production deployment, or pgvector if the team is already Postgres-native. LlamaIndex has similarly comprehensive integrations.
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