使用 Hologres 作为 OpenAI 嵌入的向量数据库

! pip install openai psycopg2-binary pandas wget

import os
import psycopg2

# Note. alternatively you can set a temporary env variable like this:
# os.environ["PGHOST"] = "your_host"
# os.environ["PGPORT"] "5432"),
# os.environ["PGDATABASE"] "postgres"),
# os.environ["PGUSER"] "user"),
# os.environ["PGPASSWORD"] "password"),

connection = psycopg2.connect(
    host=os.environ.get("PGHOST", "localhost"),
    port=os.environ.get("PGPORT", "5432"),
    database=os.environ.get("PGDATABASE", "postgres"),
    user=os.environ.get("PGUSER", "user"),
    password=os.environ.get("PGPASSWORD", "password")
)
connection.set_session(autocommit=True)

# Create a new cursor object
cursor = connection.cursor()

import wget

embeddings_url = "https://cdn.openai.com/API/examples/data/vector_database_wikipedia_articles_embedded.zip"

# The file is ~700 MB so this will take some time
wget.download(embeddings_url)

cursor.execute('CREATE EXTENSION IF NOT EXISTS proxima;')
create_proxima_table_sql = '''
BEGIN;
DROP TABLE IF EXISTS articles;
CREATE TABLE articles (
    id INT PRIMARY KEY NOT NULL,
    url TEXT,
    title TEXT,
    content TEXT,
    title_vector float4[] check(
        array_ndims(title_vector) = 1 and 
        array_length(title_vector, 1) = 1536
    ), -- define the vectors
    content_vector float4[] check(
        array_ndims(content_vector) = 1 and 
        array_length(content_vector, 1) = 1536
    ),
    vector_id INT
);

-- Create indexes for the vector fields.
call set_table_property(
    'articles',
    'proxima_vectors', 
    '{
        "title_vector":{"algorithm":"Graph","distance_method":"Euclidean","builder_params":{"min_flush_proxima_row_count" : 10}},
        "content_vector":{"algorithm":"Graph","distance_method":"Euclidean","builder_params":{"min_flush_proxima_row_count" : 10}}
    }'
);  

COMMIT;
'''

# Execute the SQL statements (will autocommit)
cursor.execute(create_proxima_table_sql)

import io

# Path to the unzipped CSV file
csv_file_path = '../../data/vector_database_wikipedia_articles_embedded.csv'

# In SQL, arrays are surrounded by {}, rather than []
def process_file(file_path):
    with open(file_path, 'r') as file:
        for line in file:
            # Replace '[' with '{' and ']' with '}'
            modified_line = line.replace('[', '{').replace(']', '}')
            yield modified_line

# Create a StringIO object to store the modified lines
modified_lines = io.StringIO(''.join(list(process_file(csv_file_path))))

# Create the COPY command for the copy_expert method
copy_command = '''
COPY public.articles (id, url, title, content, title_vector, content_vector, vector_id)
FROM STDIN WITH (FORMAT CSV, HEADER true, DELIMITER ',');
'''

# Execute the COPY command using the copy_expert method
cursor.copy_expert(copy_command, modified_lines)

cursor.execute('vacuum articles;')

import openai
def query_knn(query, table_name, vector_name="title_vector", top_k=20):

    # Creates embedding vector from user query
    embedded_query = openai.Embedding.create(
        input=query,
        model="text-embedding-3-small",
    )["data"][0]["embedding"]

    # Convert the embedded_query to PostgreSQL compatible format
    embedded_query_pg = "{" + ",".join(map(str, embedded_query)) + "}"

    # Create SQL query
    query_sql = f"""
    SELECT id, url, title, pm_approx_euclidean_distance({vector_name},'{embedded_query_pg}'::float4[]) AS distance
    FROM {table_name}
    ORDER BY distance
    LIMIT {top_k};
    """
    # Execute the query
    cursor.execute(query_sql)
    results = cursor.fetchall()

    return results