Vectors on PG Blog

Vector Databases in Practice for Java

Sat, 04 Jul 2026 00:00:00 +0000

Introduction

RAG From Scratch in Java built retrieval with nothing but an array of doubles and a Comparator: cosine similarity computed in a loop, top-k picked with a stream sort. That post said outright that this is a brute-force O(n) scan — fine for a few thousand chunks, the wrong tool once a corpus reaches millions. This post picks up exactly there: how do you store and search vectors at that scale, using Postgres, and when do you need something else entirely?

Vector Databases in Practice for Python

Sat, 04 Jul 2026 00:00:00 +0000

Introduction

RAG From Scratch in Python built retrieval with nothing but a list of floats and sorted(): cosine similarity computed in a loop, top-k picked with a slice. That post said outright that this is a brute-force O(n) scan — fine for a few thousand chunks, the wrong tool once a corpus reaches millions. This post picks up exactly there: how do you store and search vectors at that scale, using Postgres, and when do you need something else entirely?