Postgres Vector Store

Topics

• Overview
• Install dependencies
• Creating Postgres vector store
  • Connecting to an IAM auth-enabled Postgres vector store
  • TLS

Overview

You can use a Postgres database with the pgvector extension as a vector store.

Install dependencies

The Postgres vector store requires both the psycopg2 and pgvector packages:

pip install psycopg2-binary pgvector

Creating a Postgres vector store

Use the VectorStoreFactory.for_vector_store() static factory method to create an instance of a Postgres vector store.

To create a Postgres vector store, supply a connection string in the following format:

postgresql://[user[:password]@][netloc][:port][/dbname][?param1=value1&...]

For example:

postgresql://graphrag:!zfg%dGGh@mydbcluster.cluster-123456789012.us-west-2.rds.amazonaws.com:5432/postgres

Connecting to an IAM auth-enabled Postgres vector store

If your Postgres database supports AWS Identity and Access Management (IAM) database authentication, omit the password, and add enable_iam_db_auth=True to the connection string query parameters:

postgresql://graphrag@mydbcluster.cluster-123456789012.us-west-2.rds.amazonaws.com:5432/postgres?enable_iam_db_auth=True

You will need to create a database user, and grant the rds_iam role to use IAM authentication.

TLS

The connection uses TLS by default (sslmode=require), and fails if the server does not support it. To choose a different mode, add sslmode to the connection string query parameters, or set the PGSSLMODE environment variable. A mode in the connection string takes precedence over PGSSLMODE.

require encrypts the connection but does not check the server’s certificate, so another host can present any certificate and intercept it. If sslrootcert is set, or ~/.postgresql/root.crt exists, libpq verifies the server certificate against that CA even under require, as it does for verify-ca. For production, use sslmode=verify-full to verify the certificate and host name, and point sslrootcert at the CA certificate. For Amazon RDS and Aurora, that is the RDS certificate bundle:

postgresql://graphrag@mydbcluster.cluster-123456789012.us-west-2.rds.amazonaws.com:5432/postgres?enable_iam_db_auth=True&sslmode=verify-full&sslrootcert=/path/to/global-bundle.pem

A local Postgres that has no TLS configured, such as a Docker container, needs sslmode=disable:

postgresql://postgres:password@localhost:5432/graphrag?sslmode=disable