pgvector-rust

pgvector support for Rust

Supports Rust-Postgres, SQLx, and Diesel

Getting Started

Follow the instructions for your database library:

• Rust-Postgres
• SQLx
• Diesel

Rust-Postgres

Add this line to your application’s Cargo.toml under [dependencies]:

toml pgvector = { version = "0.2", features = ["postgres"] }

Create a vector from a Vec<f32>

rust let vec = pgvector::Vector::from(vec![1.0, 2.0, 3.0]);

Insert a vector

rust client.execute("INSERT INTO table (column) VALUES ($1)", &[&vec])?;

Get the nearest neighbor

rust let row = client.query_one("SELECT * FROM table ORDER BY column <-> $1 LIMIT 1", &[&vec])?;

Retrieve a vector

rust let row = client.query_one("SELECT column FROM table LIMIT 1", &[])?; let vec: pgvector::Vector = row.get(0);

Use Option if the value could be NULL

rust let res: Option<pgvector::Vector> = row.get(0);

SQLx

Add this line to your application’s Cargo.toml under [dependencies]:

toml pgvector = { version = "0.2", features = ["sqlx"] }

Create a vector from a Vec<f32>

rust let vec = pgvector::Vector::from(vec![1.0, 2.0, 3.0]);

Insert a vector

rust sqlx::query("INSERT INTO table (column) VALUES ($1)").bind(vec).execute(&pool).await?;

Get the nearest neighbors

rust let rows = sqlx::query("SELECT * FROM table ORDER BY column <-> $1 LIMIT 1") .bind(vec).fetch_all(&pool).await?;

Retrieve a vector

rust let row = sqlx::query("SELECT column FROM table LIMIT 1").fetch_one(&pool).await?; let vec: pgvector::Vector = row.try_get("column")?;

Diesel

Add this line to your application’s Cargo.toml under [dependencies]:

toml pgvector = { version = "0.2", features = ["diesel"] }

And add this line to your application’s diesel.toml under [print_schema]:

toml import_types = ["diesel::sql_types::*", "pgvector::sql_types::*"]

Create a migration

sh diesel migration generate create_vector_extension

with up.sql:

sql CREATE EXTENSION vector

and down.sql:

sql DROP EXTENSION vector

Run the migration

sql diesel migration run

You can now use the vector type in future migrations

sql CREATE TABLE items ( factors VECTOR(3) )

For models, use:

rust pub struct Item { pub factors: Option<pgvector::Vector> }

Create a vector from a Vec<f32>

rust let factors = pgvector::Vector::from(vec![1.0, 2.0, 3.0]);

Insert a vector

```rust let new_item = Item { factors: Some(factors) };

diesel::insertinto(items::table) .values(&newitem) .get_result::(&mut conn)?; ```

Get the nearest neighbors

```rust use pgvector::VectorExpressionMethods;

let neighbors = items::table .order(items::factors.l2_distance(factors)) .limit(5) .load::(&mut conn)?; ```

Also supports max_inner_product and cosine_distance

Get the distances

rust let distances = items::table .select(items::factors.l2_distance(factors)) .load::<Option<f64>>(&mut conn)?;

Add an approximate index in a migration

sql CREATE INDEX my_index ON items USING ivfflat (factors vector_l2_ops)

Use vector_ip_ops for inner product and vector_cosine_ops for cosine distance

Reference

Convert a vector to a Vec<f32>

rust let f32_vec: Vec<f32> = vec.into();

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:

sh git clone https://github.com/pgvector/pgvector-rust.git cd pgvector-rust createdb pgvector_rust_test cargo test --all-features