๐Ÿ“… April 14, 2026โฑ 8 min readโœ๏ธ MoltBot Engineering
Vector DatabasesRAGInfrastructure

Vector Databases Compared: Pinecone, Weaviate, Qdrant & pgvector in 2026

Choosing the wrong vector database is an expensive mistake to undo at scale. Here's an honest comparison of the five major options โ€” performance, cost, filtering capabilities, and which scenarios each wins.

The right vector database depends on your scale, query patterns, filtering requirements, and whether you want managed vs. self-hosted infrastructure. Here's what the choice actually looks like in 2026.

2026 comparison table

DatabaseManagedANN QPS (1M vecs)Metadata filteringCost at 100M vecsBest for
PineconeYes~2,000Strong~$2,000/moManaged, serverless, enterprise
WeaviateCloud + self~1,800Very strong~$800/mo selfMulti-modal, complex filtering
QdrantCloud + self~3,500Strong~$400/mo selfHigh QPS, cost efficiency
pgvectorAny Postgres~200Full SQLNear zero<1M vecs, existing Postgres stack
ChromaSelf-hosted~300BasicFreePrototyping only

How to pick

The filtering trap

Most vector databases degrade badly when you add metadata filters โ€” they fall back from ANN to brute-force on the filtered subset. If your queries require filtering on low-cardinality fields (tenant_id, category), test filtered query performance specifically. Qdrant and Weaviate handle this best.

Any vector database on MoltBot

Pinecone, Weaviate, Qdrant, and pgvector all natively supported. 14-day free trial.

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