pgvector-lua

pgvector support for Lua

Supports pgmoon

Getting Started

Run:

luarocks install pgvector

And follow the instructions for your database library:

• pgmoon

pgmoon

Require the library

local pgvector = require("pgvector")

Enable the extension

pg:query("CREATE EXTENSION IF NOT EXISTS vector")

Create a table

pg:query("CREATE TABLE items (id bigserial PRIMARY KEY, embedding vector(3))")

Insert a vector

embedding = pgvector.new({1, 1, 1})
pg:query("INSERT INTO items (embedding) VALUES ($1)", embedding)

Get the nearest neighbors

embedding = pgvector.new({1, 1, 1})
local res = pg:query("SELECT * FROM items ORDER BY embedding <-> $1 LIMIT 5", embedding)
for i, row in ipairs(res) do
  for k, v in pairs(row) do
    print(k, v)
  end
end

Add an approximate index

pg:query("CREATE INDEX ON items USING hnsw (embedding vector_l2_ops)")
-- or
pg:query("CREATE INDEX ON items USING ivfflat (embedding vector_l2_ops) WITH (lists = 100)")

Use vector_ip_ops for inner product and vector_cosine_ops for cosine distance

See a full example

History

View the changelog

Contributing

Everyone is encouraged to help improve this project. Here are a few ways you can help:

• Report bugs
• Fix bugs and submit pull requests
• Write, clarify, or fix documentation
• Suggest or add new features

To get started with development:

git clone https://github.com/pgvector/pgvector-lua.git
cd pgvector-lua
createdb pgvector_lua_test
luarocks install pgmoon
luarocks install luasocket
lua test/example.lua