pgvector
Hacker ApprovedThe most recommended of 14 Postgres extensions
People recommend it as an easy way to add vector search inside PostgreSQL, avoiding a separate database; critics say it struggles with very large, fast-changing indexes.
People recommend it as an easy way to add vector search inside PostgreSQL, avoiding a separate database; critics say it struggles with very large, fast-changing indexes.
75 people gave an opinion
- recommend it
- 55
- criticize it
- 20
- approval share
- 73%
Recommended in 10 of 13 months
- November 2025: recommended
- December 2025: recommended
- January 2026: recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: recommended
- July 2026: recommended
- August 2026: recommended
- September 2026: not recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it carries the badge
- 55 people recommend itNeeds 10 or more, met.
- 2.8 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 10 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Fast enough for many workloads
“pgvector HNSW indexes (m=64, ef_construction=200) give you sub-100ms semantic search without leaving Postgres”
Comment from 23 Nov 2025 in “Show HN: I made it fast and easy to launch your own RAG-powered AI chatbots” “Even without fancy indexing, a full scan (1 search vector -> 5M stored vectors), takes less than 40ms.”
Comment from 3 Nov 2025 in “The Case Against PGVector” “have seen very fast lookups with pgvector (HNSW index) and sqlite-vec on 20k vectors”
Comment from 1 Feb 2026 in “Tuning Semantic Search on Jfmm.net” - Comment from 16 Dec 2025 in “7 Years, 2 Rebuilds, 40K+ Stars: Milvus Recap and Roadmap”
- Comment from 22 Nov 2025 in “Show HN: ChatRAG – Next.js and AI SDK starter to ship RAG chatbots faster”
Easy to set up and use
“you can just add the pgvector extension determine what embeddings that you want to use and try it out without committing to much”
Comment from 22 Nov 2025 in “Ask HN: How would you architect a RAG system for 10M+ documents today?” “I was genuinely surprised just how easy it was to get a fully working RAG set up with Postgres.”
Comment from 8 Mar 2026 in “You Don't Need a Vector Database” “surely the easiest solution is to run `CREATE EXTENSION vector`”
Comment from 8 Mar 2026 in “You Don't Need a Vector Database” - Comment from 8 Mar 2026 in “You Don't Need a Vector Database”
Keeps vectors next to relational data
“PostgreSQL with pgvector now supports HNSW indexing, meaning you can keep your vectors right next to your relational data.”
Comment from 1 Mar 2026 on Hacker News “if you're already running postgres with pgvector, you're in a good spot”
Comment from 8 Mar 2026 in “You Don't Need a Vector Database” “pgvector could handle their use case with less operational overhead”
Comment from 5 Mar 2026 in “Show HN: PostgreSQL for AI – A book on pgvector, RAG, and in-database ML” - Comment from 2 Mar 2026 in “Show HN: Omni – Open-source workplace search and chat, built on Postgres”
Works for hybrid text and vector search
“I've been doing some RAG prototypes with hybrid search using pg_textsearch plus pgvector and have been very pleased with the results.”
Comment from 31 Mar 2026 in “Show HN: How This Graybeard Built the Fastest and Freest Postgres BM25 Search” “pgvector + tsvector (for hybrid search) seems like the most logical MVP”
Comment from 24 Nov 2025 in “Ask HN: How would you architect a RAG system for 10M+ documents today?” “hybrid search ( plpgsql_bm25 + pgvector ) with Reciprocal Rank Fusion”
Comment from 20 Aug 2026 in “PostgreSQL for Everything” - Comment from 15 Jan 2026 in “Ask HN: How are you doing RAG locally?”
What people warn about
Each mark is one comment
Scaling limits at very large sizes
“the limitations of pgvector are very real when you're talking indices that grow beyond millions of things”
Comment from 3 Nov 2025 in “The Case Against PGVector” “found Postgres to be unsuitable at several orders of magnitude less than we currently have”
Comment from 3 Nov 2025 in “The Case Against PGVector” “pgvector just doesn't really scale to the kinds of workloads we ran here”
Comment from 3 Dec 2025 in “Real-world vector DB performance across the most popular providers” - Comment from 30 Dec 2025 in “Postgres extension complements pgvector for performance and scale”
Struggles with high-velocity inserts
“But they’re all workarounds for the fact that pgvector wasn’t really designed for high-velocity real-time ingestion.”
Comment from 3 Nov 2025 in “The Case Against PGVector” “Postgres isn't built from the ground-up for high-velocity vector insertions”
Comment from 4 Nov 2025 in “The Case Against PGVector” “can support 15x more updates per second comparing to pgvector's HNSW”
Comment from 3 Nov 2025 in “The Case Against PGVector” Index rebuilds and high memory use
“Vacuuming is grief enough. Rebuilding the index sounds like more of a nightmare than with Solr/Lucene.”
Comment from 4 Nov 2025 in “The Case Against PGVector” “IVFFlat indexes have to be periodically rebuilt, that HNSW has high overhead”
Comment from 4 Nov 2025 in “The Case Against PGVector” “HNSW index on a few million vectors can consume 10+ GB of RAM or more”
Comment from 3 Nov 2025 in “The Case Against PGVector” Hard to predict filtering behavior
“pg_vector's economics can be much worse, especially in multi-tenant scenarios”
Comment from 22 Jan 2026 in “ANN v3: 200ms p99 query latency over 100B vectors” “it's hard to predict when postgres will decide to use pre- vs post-filtering”
Comment from 3 Nov 2025 in “The Case Against PGVector”
Other Postgres extensions people recommend
The four most recommended other Postgres extensions, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| pgvectorThis page | 55 | 20 | 73% | 10 | — | Approved |
| PostGIS | 20 | 3 | 87% | 8 | — | Approved |
| pg_lake | 18 | 3 | 86% | 5 | — | Approved |
| ParadeDB | 13 | 1 | 93% | 8 | — | Approved |
| pg_textsearch | 10 | 0 | 100% | 7 | — | Approved |
What people said
40 of the 84 comments that mention it, newest first. Each links to the original comment.
“hybrid search ( plpgsql_bm25 + pgvector ) with Reciprocal Rank Fusion”
“I used this in a different project (halfvec in pgvector) without affecting results”
“you can use quantized vector indexes[0] (handled by pgvector) which will get past the limits imposed by PostgreSQL.”
“a knowledge graph and pgvector which accounts for most of the performance”
“I've been doing some RAG prototypes with hybrid search using pg_textsearch plus pgvector and have been very pleased with the results.”
“I was genuinely surprised just how easy it was to get a fully working RAG set up with Postgres.”
“if you're already running postgres with pgvector, you're in a good spot”
“pgvector is great if you're already on postgres and only need text search”
“Pgvector is definitely the easiest way to get started.”
“surely the easiest solution is to run `CREATE EXTENSION vector`”
“pgvector could handle their use case with less operational overhead”
“pgvector's HNSW indexes handle the approximate nearest neighbor search well enough for workplace search”
“it's certainly simpler than bolting another solution for it”
“PostgreSQL with pgvector now supports HNSW indexing, meaning you can keep your vectors right next to your relational data.”
“have seen very fast lookups with pgvector (HNSW index) and sqlite-vec on 20k vectors”
“pg_vector's economics can be much worse, especially in multi-tenant scenarios”
“You can use pgvector for the vector lookup and paradedb for bm25.”
“something pgvector itself wasn't able to handle in a reasonable amount of time”
“We regularly do tens of thousands of QPS on pgvector fine on massive data stores.”
“pgvector just doesn't really scale to the kinds of workloads we ran here”
“pgvector + tsvector (for hybrid search) seems like the most logical MVP”
“pgvector HNSW indexes (m=64, ef_construction=200) give you sub-100ms semantic search without leaving Postgres”
“Fast approximate nearest neighbor search directly in Postgres”
“you can just add the pgvector extension determine what embeddings that you want to use and try it out without committing to much”
“We actively use pgvector in a production setting for maintaining and querying HNSW vector indexes”
“Vacuuming is grief enough. Rebuilding the index sounds like more of a nightmare than with Solr/Lucene.”
“IVFFlat indexes have to be periodically rebuilt, that HNSW has high overhead”
“Postgres isn't built from the ground-up for high-velocity vector insertions”
“the limitations of pgvector are very real when you're talking indices that grow beyond millions of things”
“found Postgres to be unsuitable at several orders of magnitude less than we currently have”
“He doesn't point to a single thing that pg_vector doesn't do or doesn't do well.”
“Even without fancy indexing, a full scan (1 search vector -> 5M stored vectors), takes less than 40ms.”
“If you need vector search against 100,000 vectors and you already have PostgreSQL then pgvector is a great YAGNI solution.”
“But they’re all workarounds for the fact that pgvector wasn’t really designed for high-velocity real-time ingestion.”
“HNSW index on a few million vectors can consume 10+ GB of RAM or more”
“it's hard to predict when postgres will decide to use pre- vs post-filtering”
“as the author noted is not without some flaws and are typically in the smallish range”
“all the mentioned issues are resolved, I will favour in using the PGVector”
“can support 15x more updates per second comparing to pgvector's HNSW”
“We do at Discourse, in thousands of databases, and it's leveraged in most of the billions of page views we serve.”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.