AlloyDB is a fully managed relational database service that offers high performance, seamless integration, and impressive scalability. AlloyDB is 100% compatible with PostgreSQL. Extend your database application to build AI-powered experiences leveraging AlloyDB's Langchain integrations.

This notebook goes over how to useAlloyDB for PostgreSQL to load Documents with theAlloyDBLoader class.

Learn more about the package onGitHub.

Before you begin​

To run this notebook, you will need to do the following:

• Create a Google Cloud Project
• Enable the AlloyDB API
• Create a AlloyDB cluster and instance.
• Create a AlloyDB database.
• Add a User to the database.

🦜🔗 Library Installation​

Install the integration library,langchain-google-alloydb-pg.

%pip install--upgrade--quiet  langchain-google-alloydb-pg

Colab only: Uncomment the following cell to restart the kernel or use the button to restart the kernel. For Vertex AI Workbench you can restart the terminal using the button on top.

# # Automatically restart kernel after installs so that your environment can access the new packages
# import IPython

# app = IPython.Application.instance()
# app.kernel.do_shutdown(True)

🔐 Authentication​

Authenticate to Google Cloud as the IAM user logged into this notebook in order to access your Google Cloud Project.

• If you are using Colab to run this notebook, use the cell below and continue.
• If you are using Vertex AI Workbench, check out the setup instructionshere.

from google.colabimport auth

auth.authenticate_user()

☁ Set Your Google Cloud Project​

Set your Google Cloud project so that you can leverage Google Cloud resources within this notebook.

If you don't know your project ID, try the following:

• Rungcloud config list.
• Rungcloud projects list.
• See the support page:Locate the project ID.

# @title Project { display-mode: "form" }
PROJECT_ID="gcp_project_id"# @param {type:"string"}

# Set the project id
! gcloud configset project{PROJECT_ID}

Basic Usage​

Set AlloyDB database variables​

Find your database values, in theAlloyDB Instances page.

# @title Set Your Values Here { display-mode: "form" }
REGION="us-central1"# @param {type: "string"}
CLUSTER="my-cluster"# @param {type: "string"}
INSTANCE="my-primary"# @param {type: "string"}
DATABASE="my-database"# @param {type: "string"}
TABLE_NAME="vector_store"# @param {type: "string"}

AlloyDBEngine Connection Pool​

One of the requirements and arguments to establish AlloyDB as a vector store is aAlloyDBEngine object. TheAlloyDBEngine configures a connection pool to your AlloyDB database, enabling successful connections from your application and following industry best practices.

To create aAlloyDBEngine usingAlloyDBEngine.from_instance() you need to provide only 5 things:

1. project_id : Project ID of the Google Cloud Project where the AlloyDB instance is located.
2. region : Region where the AlloyDB instance is located.
3. cluster: The name of the AlloyDB cluster.
4. instance : The name of the AlloyDB instance.
5. database : The name of the database to connect to on the AlloyDB instance.

By default,IAM database authentication will be used as the method of database authentication. This library uses the IAM principal belonging to theApplication Default Credentials (ADC) sourced from the environment.

Optionally,built-in database authentication using a username and password to access the AlloyDB database can also be used. Just provide the optionaluser andpassword arguments toAlloyDBEngine.from_instance():

• user : Database user to use for built-in database authentication and login
• password : Database password to use for built-in database authentication and login.

Note: This tutorial demonstrates the async interface. All async methods have corresponding sync methods.

from langchain_google_alloydb_pgimport AlloyDBEngine

engine=await AlloyDBEngine.afrom_instance(
    project_id=PROJECT_ID,
    region=REGION,
    cluster=CLUSTER,
    instance=INSTANCE,
    database=DATABASE,
)

Create AlloyDBLoader​

from langchain_google_alloydb_pgimport AlloyDBLoader

# Creating a basic AlloyDBLoader object
loader=await AlloyDBLoader.create(engine, table_name=TABLE_NAME)

Load Documents via default table​

The loader returns a list of Documents from the table using the first column as page_content and all other columns as metadata. The default table will have the first column aspage_content and the second column as metadata (JSON). Each row becomes a document.

docs=await loader.aload()
print(docs)

Load documents via custom table/metadata or custom page content columns​

loader=await AlloyDBLoader.create(
    engine,
    table_name=TABLE_NAME,
    content_columns=["product_name"],# Optional
    metadata_columns=["id"],# Optional
)
docs=await loader.aload()
print(docs)

Set page content format​

The loader returns a list of Documents, with one document per row, with page content in specified string format, i.e. text (space separated concatenation), JSON, YAML, CSV, etc. JSON and YAML formats include headers, while text and CSV do not include field headers.

loader= AlloyDBLoader.create(
    engine,
    table_name="products",
    content_columns=["product_name","description"],
format="YAML",
)
docs=await loader.aload()
print(docs)

Related​

• Document loaderconceptual guide
• Document loaderhow-to guides