# On-disk HNSW index for Postgres with pg\_embedding

DevFeed: [On-disk HNSW index for Postgres with pg\_embedding](<https://devfeed.tech/articles/on-disk-hnsw-index-for-postgres-with-pg-embedding-5716.md>)

Original publisher: [Read original article](<https://neon.com/blog/pg_embedding-on-disk-hnsw-index>)

Author: Mahmoud Abdelwahab

Published: 2023-08-03T16:00:42Z

Content type: release

Language: en

Sources: [Blog -- Neon Docs](<https://devfeed.tech/sources/blog-neon-docs.md>)

Topics: [Embeddings](<https://devfeed.tech/topics/embeddings.md>), [Database](<https://devfeed.tech/topics/database.md>), [LangChain](<https://devfeed.tech/topics/langchain.md>), [autoscaling](<https://devfeed.tech/topics/autoscaling.md>)

Tags: [ai](<https://devfeed.tech/tags/ai.md>), [autoscaling](<https://devfeed.tech/tags/autoscaling.md>), [database](<https://devfeed.tech/tags/database.md>), [embedding](<https://devfeed.tech/tags/embedding.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [langchain](<https://devfeed.tech/tags/langchain.md>), [llm](<https://devfeed.tech/tags/llm.md>), [postgres](<https://devfeed.tech/tags/postgres.md>), [release](<https://devfeed.tech/tags/release.md>), [scale](<https://devfeed.tech/tags/scale.md>), [search](<https://devfeed.tech/tags/search.md>), [vector](<https://devfeed.tech/tags/vector.md>)

## AI overview

This release updates pg_embedding with on-disk HNSW index construction and support for cosine similarity, Manhattan distance, and Euclidean distance. It explains how vector embeddings can be stored in Postgres and queried for similarity without an external vector store, while highlighting Neon scaling features for AI and LLM applications.

## Source excerpt

A few weeks back, we released pg_embedding, a new extension for Postgres and LangChain which introduced Hierarchical Navigable Small Worlds (HNSW) indexes for vector similarity search. This new indexing method resulted in 20x faster queries at a 99% accuracy compared to tradition...