Sentence Transformers

Setup a products table. Copy from the example data provided by the extension.

Ensure vectorize.embedding_svc_url is set to the URL of the vector-serve container.

If you’re running this example using the docker-compose.yaml file from this repo, it should look like this:

SHOW vectorize.embedding_service_url;

    vectorize.embedding_service_url     
----------------------------------------
 http://vector-serve:3000/v1/embeddings
(1 row)

If you are not running in docker, then you will need to change the url to the appropriate location. If that is localhost, it would look like this;

ALTER SYSTEM SET vectorize.embedding_svc_url TO 'http://localhost:3000/v1/embeddings';

Then reload Postgres configurations:

SELECT pg_reload_conf();

Create an example table if it does not already exist.

CREATE TABLE products (LIKE vectorize.example_products INCLUDING ALL);
INSERT INTO products SELECT * FROM vectorize.example_products;

SELECT * FROM products limit 2;

 product_id | product_name |                      description                       |        last_updated_at        
------------+--------------+--------------------------------------------------------+-------------------------------
          1 | Pencil       | Utensil used for writing and often works best on paper | 2023-07-26 17:20:43.639351-05
          2 | Laptop Stand | Elevated platform for laptops, enhancing ergonomics    | 2023-07-26 17:20:43.639351-05

Create a job to vectorize the products table. We’ll specify the tables primary key (product_id) and the columns that we want to search (product_name and description).

SELECT vectorize.table(
    job_name => 'product_search_hf',
    "table" => 'products',
    primary_key => 'product_id',
    columns => ARRAY['product_name', 'description'],
    transformer => 'sentence-transformers/multi-qa-MiniLM-L6-dot-v1'
);

This adds a new column to your table, in our case it is named product_search_embeddings, then populates that data with the transformed embeddings from the product_name and description columns.

Then search,

SELECT * FROM vectorize.search(
    job_name => 'product_search_hf',
    query => 'accessories for mobile devices',
    return_columns => ARRAY['product_id', 'product_name'],
    num_results => 3
);

                                       search_results                                        
---------------------------------------------------------------------------------------------
 {"product_id": 13, "product_name": "Phone Charger", "similarity_score": 0.8147814132322894}
 {"product_id": 6, "product_name": "Backpack", "similarity_score": 0.7743061352550308}
 {"product_id": 11, "product_name": "Stylus Pen", "similarity_score": 0.7709902653575383}