Lesson 1.2

Vector databases and indexes

Exact nearest-neighbour search does not scale, so vector indexes trade a little recall for a lot of speed. Knowing the trade-off keeps you out of trouble.

Taught byPriya RamanLLMs · RAG · Prompt engineering · Evaluation
4m Advanced 8,658 students

Overview

Exact nearest-neighbour search does not scale, so vector indexes trade a little recall for a lot of speed. Knowing the trade-off keeps you out of trouble.

What this lesson covers

  • Understand approximate nearest neighbour search
  • Trade recall against latency deliberately
  • Store metadata alongside vectors for filtering

This lesson sits in Embeddings and Vector Search, part of Retrieval-Augmented Generation from Scratch. It assumes what came before it and leads directly into the next lesson in the module.

In this lesson you will:

  • Understand approximate nearest neighbour search
  • Trade recall against latency deliberately
  • Store metadata alongside vectors for filtering

Resources