LLM Rag Example

Mix.install([
  {:bumblebee, "~> 0.6.0"},
  {:nx, "~> 0.9.2"},
  {:emlx, github: "elixir-nx/emlx"},
  {:text_chunker, "~> 0.3.1"},
  {:postgrex, "~> 0.19.1"},
  {:pgvector, "~> 0.3.0"},
  {:ecto_sql, "~> 3.12"},
])

Nx.default_backend({EMLX.Backend, device: :gpu})

Define pg vector type

Postgrex.Types.define(
  RAG.PostgrexTypes, 
  Pgvector.extensions() ++ Ecto.Adapters.Postgres.extensions(), 
  []
)

Setup Ecto

defmodule RAG.Repo do
  use Ecto.Repo,
    otp_app: :rag,
    adapter: Ecto.Adapters.Postgres
end

defmodule RAG.Document do
  use Ecto.Schema

  schema "documents" do
    field :content, :string
    field :embedding, Pgvector.Ecto.Vector
  end
end

RAG.Repo.start_link(
  hostname: "localhost",
  username: "zacksiri",
  password: "",
  database: "rag_example",
  types: RAG.PostgrexTypes
)
|> case do
  {:ok, pg} -> {:ok, pg}
  {:error, {:already_started, pg}} -> {:ok, pg}
end

RAG.Repo.query!("create extension if not exists vector;")