Generate image embeddings by using the AI.GENERATE_EMBEDDING function
This document shows you how to create a BigQuery MLremote modelthat references aVertex AI embedding model.You then use that model with theAI.GENERATE_EMBEDDING functionto create image embeddings by using data from aBigQueryobject table.
Required roles
To create a remote model and generate embeddings, you need thefollowing Identity and Access Management (IAM) roles:
- Create and use BigQuery datasets, tables, and models:BigQuery Data Editor (
roles/bigquery.dataEditor) on your project. Create, delegate, and use BigQuery connections:BigQuery Connections Admin (
roles/bigquery.connectionsAdmin) on yourproject.If you don't have adefault connectionconfigured, you can create and set one as part of running the
CREATE MODELstatement. To do so, you must have BigQuery Admin(roles/bigquery.admin) on your project. For more information, seeConfigure the default connection.Grant permissions to the connection's service account: Project IAM Admin(
roles/resourcemanager.projectIamAdmin) on the project that contains theVertex AI endpoint. This is the current project for remote modelsthat you create by specifying the model name as an endpoint. This is theproject identified in the URL for remote models that you create byspecifying a URL as an endpoint.If you use the remote model to analyze unstructured data from an objecttable, and the Cloud Storage bucket that you use in the object table isin a different project than your Vertex AI endpoint, you mustalso have Storage Admin (
roles/storage.admin) on theCloud Storage bucket used by the object table.Create BigQuery jobs: BigQuery Job User(
roles/bigquery.jobUser) on your project.
These predefined roles contain the permissions required to perform the tasks inthis document. To see the exact permissions that are required, expand theRequired permissions section:
Required permissions
- Create a dataset:
bigquery.datasets.create - Create, delegate, and use a connection:
bigquery.connections.* - Set service account permissions:
resourcemanager.projects.getIamPolicyandresourcemanager.projects.setIamPolicy - Create an object table:
bigquery.tables.createandbigquery.tables.update - Create a model and run inference:
bigquery.jobs.createbigquery.models.createbigquery.models.getDatabigquery.models.updateDatabigquery.models.updateMetadata
You might also be able to get these permissions withcustom roles or otherpredefined roles.
Before you begin
In the Google Cloud console, on the project selector page, select or create a Google Cloud project.
Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.Roles required to select or create a project
- Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
- Create a project: To create a project, you need the Project Creator role (
roles/resourcemanager.projectCreator), which contains theresourcemanager.projects.createpermission.Learn how to grant roles.
Verify that billing is enabled for your Google Cloud project.
Enable the BigQuery, BigQuery Connection, Cloud Storage, and Vertex AI APIs.
Roles required to enable APIs
To enable APIs, you need the Service Usage Admin IAM role (
roles/serviceusage.serviceUsageAdmin), which contains theserviceusage.services.enablepermission.Learn how to grant roles.
Create a dataset
Create a BigQuery dataset to contain your resources:
Console
In the Google Cloud console, go to theBigQuery page.
In the left pane, clickExplorer:

If you don't see the left pane, clickExpand left pane to open the pane.
In theExplorer pane, click your project name.
ClickView actions > Create dataset.
On theCreate dataset page, do the following:
ForDataset ID, type a name for the dataset.
ForLocation type, selectRegion orMulti-region.
- If you selectedRegion, then select a location from theRegion list.
- If you selectedMulti-region, then selectUS orEuropefrom theMulti-region list.
ClickCreate dataset.
bq
Create a connection
Create aCloud resource connectionand get the connection's service account. Create the connection inthe samelocation as the dataset you created in theprevious step.
You can skip this step if you either have a default connection configured, oryou have the BigQuery Admin role.
Select one of the following options:Console
Go to theBigQuery page.
In the left pane, clickExplorer:

If you don't see the left pane, clickExpand left pane to open the pane.
In theExplorer pane, expand your project name, and then clickConnections.
On theConnections page, clickCreate connection.
ForConnection type, chooseVertex AI remote models, remotefunctions, BigLake and Spanner (Cloud Resource).
In theConnection ID field, enter a name for your connection.
ForLocation type, select a location for your connection. Theconnection should be colocated with your other resources such asdatasets.
ClickCreate connection.
ClickGo to connection.
In theConnection info pane, copy the service account ID for use ina later step.
bq
In a command-line environment, create a connection:
bqmk--connection--location=REGION--project_id=PROJECT_ID\--connection_type=CLOUD_RESOURCECONNECTION_ID
The
--project_idparameter overrides the default project.Replace the following:
REGION: yourconnection regionPROJECT_ID: your Google Cloud project IDCONNECTION_ID: an ID for yourconnection
When you create a connection resource, BigQuery creates aunique system service account and associates it with the connection.
Troubleshooting: If you get the following connection error,update the Google Cloud SDK:
Flags parsing error: flag --connection_type=CLOUD_RESOURCE: value should be one of...
Retrieve and copy the service account ID for use in a laterstep:
bqshow--connectionPROJECT_ID.REGION.CONNECTION_ID
The output is similar to the following:
name properties1234.REGION.CONNECTION_ID {"serviceAccountId": "connection-1234-9u56h9@gcp-sa-bigquery-condel.iam.gserviceaccount.com"}
Python
Before trying this sample, follow thePython setup instructions in theBigQuery quickstart using client libraries. For more information, see theBigQueryPython API reference documentation.
To authenticate to BigQuery, set up Application Default Credentials. For more information, seeSet up authentication for client libraries.
importgoogle.api_core.exceptionsfromgoogle.cloudimportbigquery_connection_v1client=bigquery_connection_v1.ConnectionServiceClient()defcreate_connection(project_id:str,location:str,connection_id:str,):"""Creates a BigQuery connection to a Cloud Resource. Cloud Resource connection creates a service account which can then be granted access to other Google Cloud resources for federated queries. Args: project_id: The Google Cloud project ID. location: The location of the connection (for example, "us-central1"). connection_id: The ID of the connection to create. """parent=client.common_location_path(project_id,location)connection=bigquery_connection_v1.Connection(friendly_name="Example Connection",description="A sample connection for a Cloud Resource.",cloud_resource=bigquery_connection_v1.CloudResourceProperties(),)try:created_connection=client.create_connection(parent=parent,connection_id=connection_id,connection=connection)print(f"Successfully created connection:{created_connection.name}")print(f"Friendly name:{created_connection.friendly_name}")print(f"Service Account:{created_connection.cloud_resource.service_account_id}")exceptgoogle.api_core.exceptions.AlreadyExists:print(f"Connection with ID '{connection_id}' already exists.")print("Please use a different connection ID.")exceptExceptionase:print(f"An unexpected error occurred while creating the connection:{e}")Node.js
Before trying this sample, follow theNode.js setup instructions in theBigQuery quickstart using client libraries. For more information, see theBigQueryNode.js API reference documentation.
To authenticate to BigQuery, set up Application Default Credentials. For more information, seeSet up authentication for client libraries.
const{ConnectionServiceClient}=require('@google-cloud/bigquery-connection').v1;const{status}=require('@grpc/grpc-js');constclient=newConnectionServiceClient();/** * Creates a new BigQuery connection to a Cloud Resource. * * A Cloud Resource connection creates a service account that can be granted access * to other Google Cloud resources. * * @param {string} projectId The Google Cloud project ID. for example, 'example-project-id' * @param {string} location The location of the project to create the connection in. for example, 'us-central1' * @param {string} connectionId The ID of the connection to create. for example, 'example-connection-id' */asyncfunctioncreateConnection(projectId,location,connectionId){constparent=client.locationPath(projectId,location);constconnection={friendlyName:'Example Connection',description:'A sample connection for a Cloud Resource',// The service account for this cloudResource will be created by the API.// Its ID will be available in the response.cloudResource:{},};constrequest={parent,connectionId,connection,};try{const[response]=awaitclient.createConnection(request);console.log(`Successfully created connection:${response.name}`);console.log(`Friendly name:${response.friendlyName}`);console.log(`Service Account:${response.cloudResource.serviceAccountId}`);}catch(err){if(err.code===status.ALREADY_EXISTS){console.log(`Connection '${connectionId}' already exists.`);}else{console.error(`Error creating connection:${err.message}`);}}}Terraform
Use thegoogle_bigquery_connectionresource.
To authenticate to BigQuery, set up Application DefaultCredentials. For more information, seeSet up authentication for client libraries.
The following example creates a Cloud resource connection namedmy_cloud_resource_connection in theUS region:
# This queries the provider for project information.data "google_project" "default" {}# This creates a cloud resource connection in the US region named my_cloud_resource_connection.# Note: The cloud resource nested object has only one output field - serviceAccountId.resource "google_bigquery_connection" "default" { connection_id = "my_cloud_resource_connection" project = data.google_project.default.project_id location = "US" cloud_resource {}}To apply your Terraform configuration in a Google Cloud project, complete the steps in the following sections.
Prepare Cloud Shell
- LaunchCloud Shell.
Set the default Google Cloud project where you want to apply your Terraform configurations.
You only need to run this command once per project, and you can run it in any directory.
export GOOGLE_CLOUD_PROJECT=PROJECT_ID
Environment variables are overridden if you set explicit values in the Terraform configuration file.
Prepare the directory
Each Terraform configuration file must have its own directory (alsocalled aroot module).
- InCloud Shell, create a directory and a new file within that directory. The filename must have the
.tfextension—for examplemain.tf. In this tutorial, the file is referred to asmain.tf.mkdirDIRECTORY && cdDIRECTORY && touch main.tf
If you are following a tutorial, you can copy the sample code in each section or step.
Copy the sample code into the newly created
main.tf.Optionally, copy the code from GitHub. This is recommended when the Terraform snippet is part of an end-to-end solution.
- Review and modify the sample parameters to apply to your environment.
- Save your changes.
- Initialize Terraform. You only need to do this once per directory.
terraform init
Optionally, to use the latest Google provider version, include the
-upgradeoption:terraform init -upgrade
Apply the changes
- Review the configuration and verify that the resources that Terraform is going to create or update match your expectations:
terraform plan
Make corrections to the configuration as necessary.
- Apply the Terraform configuration by running the following command and entering
yesat the prompt:terraform apply
Wait until Terraform displays the "Apply complete!" message.
- Open your Google Cloud project to view the results. In the Google Cloud console, navigate to your resources in the UI to make sure that Terraform has created or updated them.
Give the service account access
Grant the connection's service account the Vertex AI User andStorage Object Viewer roles.
If you plan to specify the endpoint as a URL when you create the remote model,for exampleendpoint = 'https://us-central1-aiplatform.googleapis.com/v1/projects/myproject/locations/us-central1/publishers/google/models/gemini-2.0-flash',grant these roles in the same project you specify in the URL.
If you plan to specify the endpoint by using the model name when you createthe remote model, for exampleendpoint = 'gemini-2.0-flash', grant these rolesin the same project where you plan to create the remote model.
Granting the role in a different project results in the errorbqcx-1234567890-wxyz@gcp-sa-bigquery-condel.iam.gserviceaccount.com does not have the permission to access resource.
To grant these roles, follow these steps:
Console
Go to theIAM & Admin page.
ClickAdd.
TheAdd principals dialog opens.
In theNew principals field, enter the service account ID that youcopied earlier.
In theSelect a role field, selectVertex AI, and then selectVertex AI User.
ClickAdd another role.
In theSelect a role field, chooseCloud Storage, and thenselectStorage Object Viewer.
ClickSave.
gcloud
Use thegcloud projects add-iam-policy-binding command.
gcloud projects add-iam-policy-binding 'PROJECT_NUMBER' --member='serviceAccount:MEMBER' --role='roles/aiplatform.user' --condition=Nonegcloud projects add-iam-policy-binding 'PROJECT_NUMBER' --member='serviceAccount:MEMBER' --role='roles/storage.objectViewer' --condition=None
Replace the following:
PROJECT_NUMBER: the project number of the project in which to grant the role.MEMBER: the service account ID that you copied earlier.
Create an object table
To analyze images without moving them from Cloud Storage, create anobject table.
To create an object table:
SQL
Use theCREATE EXTERNAL TABLE statement.
In the Google Cloud console, go to theBigQuery page.
In the query editor, enter the following statement:
CREATEEXTERNALTABLE`PROJECT_ID.DATASET_ID.TABLE_NAME`WITHCONNECTION{`PROJECT_ID.REGION.CONNECTION_ID`|DEFAULT}OPTIONS(object_metadata='SIMPLE',uris=['BUCKET_PATH'[,...]],max_staleness=STALENESS_INTERVAL,metadata_cache_mode='CACHE_MODE');
Replace the following:
PROJECT_ID: your project ID.DATASET_ID: the ID of thedataset that you created.TABLE_NAME: the name of the object table.REGION: theregion or multi-region that contains the connection.CONNECTION_ID: the ID of theconnection that you created.When youview the connection details in the Google Cloud console, this is the value in the last section of the fully qualified connection ID that is shown inConnection ID, for example
projects/myproject/locations/connection_location/connections/myconnection.To use a default connection, specify
DEFAULTinstead of the connection string containingPROJECT_ID.REGION.CONNECTION_ID.BUCKET_PATH: the path to the Cloud Storage bucket that contains the images, in the format['gs://bucket_name/[folder_name/]*'].The Cloud Storage bucket that you use should be in the same project where you plan to create the model and call the
AI.GENERATE_EMBEDDINGfunction. If you want to call theAI.GENERATE_EMBEDDINGfunction in a different project than the one that contains the Cloud Storage bucket used by the object table, you mustgrant the Storage Admin role at the bucket level to theservice-A@gcp-sa-aiplatform.iam.gserviceaccount.comservice account.STALENESS_INTERVAL: specifies whether cached metadata is used by operations against the object table, and how fresh the cached metadata must be in order for the operation to use it. For more information on metadata caching considerations, seeMetadata caching for performance.To disable metadata caching, specify 0. This is the default.
To enable metadata caching, specify aninterval literal value between 30 minutes and 7 days. For example, specify
INTERVAL 4 HOURfor a 4 hour staleness interval. With this value, operations against the table use cached metadata if it has been refreshed within the past 4 hours. If the cached metadata is older than that, the operation retrieves metadata from Cloud Storage instead.CACHE_MODE: specifies whether the metadata cache is refreshed automatically or manually. For more information on metadata caching considerations, seeMetadata caching for performance.Set to
AUTOMATICfor the metadata cache to be refreshed at a system-defined interval, usually somewhere between 30 and 60 minutes.Set to
MANUALif you want to refresh the metadata cache on a schedule you determine. In this case, you can call theBQ.REFRESH_EXTERNAL_METADATA_CACHEsystem procedure to refresh the cache.You must set
CACHE_MODEifSTALENESS_INTERVALis set to a value greater than 0.
ClickRun.
For more information about how to run queries, seeRun an interactive query.
bq
Use thebq mk command.
bqmk--table\--external_table_definition=BUCKET_PATH@REGION.CONNECTION_ID\--object_metadata=SIMPLE\--max_staleness=STALENESS_INTERVAL\--metadata_cache_mode=CACHE_MODE\PROJECT_ID:DATASET_ID.TABLE_NAME
Replace the following:
BUCKET_PATH: the path to the Cloud Storage bucket that contains the images, in the format['gs://bucket_name/[folder_name/]*'].The Cloud Storage bucket that you use should be in the same project where you plan to create the model and call the
AI.GENERATE_EMBEDDINGfunction. If you want to call theAI.GENERATE_EMBEDDINGfunction in a different project than the one that contains the Cloud Storage bucket used by the object table, you mustgrant the Storage Admin role at the bucket level to theservice-A@gcp-sa-aiplatform.iam.gserviceaccount.comservice account.REGION: theregion or multi-region that contains the connection.CONNECTION_ID: the ID of theconnection that you created.When youview the connection details in the Google Cloud console, this is the value in the last section of the fully qualified connection ID that is shown inConnection ID, for example
projects/myproject/locations/connection_location/connections/myconnection.STALENESS_INTERVAL: specifies whether cached metadata is used by operations against the object table, and how fresh the cached metadata must be in order for the operation to use it. For more information on metadata caching considerations, seeMetadata caching for performance.To disable metadata caching, specify 0. This is the default.
To enable metadata caching, specify aninterval literal value between 30 minutes and 7 days. For example, specify
INTERVAL 4 HOURfor a 4 hour staleness interval. With this value, operations against the table use cached metadata if it has been refreshed within the past 4 hours. If the cached metadata is older than that, the operation retrieves metadata from Cloud Storage instead.CACHE_MODE: specifies whether the metadata cache is refreshed automatically or manually. For more information on metadata caching considerations, seeMetadata caching for performance.Set to
AUTOMATICfor the metadata cache to be refreshed at a system-defined interval, usually somewhere between 30 and 60 minutes.Set to
MANUALif you want to refresh the metadata cache on a schedule you determine. In this case, you can call theBQ.REFRESH_EXTERNAL_METADATA_CACHEsystem procedure to refresh the cache.You must set
CACHE_MODEifSTALENESS_INTERVALis set to a value greater than 0.PROJECT_ID: your project ID.DATASET_ID: the ID of thedataset that you created.TABLE_NAME: the name of the object table.
Create a model
In the Google Cloud console, go to theBigQuery page.
Using the SQL editor, create aremote model:
CREATEORREPLACEMODEL`PROJECT_ID.DATASET_ID.MODEL_NAME`REMOTEWITHCONNECTION{DEFAULT|`PROJECT_ID.REGION.CONNECTION_ID`}OPTIONS(ENDPOINT='ENDPOINT');
Replace the following:
PROJECT_ID: your project ID.DATASET_ID: the ID of thedataset that you created previously.MODEL_NAME: the name of the model.REGION: theregion or multi-region that contains the connection.CONNECTION_ID: the ID of theconnection that you created.When youview the connection details in the Google Cloud console, this is the value in the last section of the fully qualified connection ID that is shown inConnection ID, for example
projects/myproject/locations/connection_location/connections/myconnection.ENDPOINT: theembedding model to use, in this casemultimodalembedding@001.If you specify a URL as the endpoint when you create the remote model, for example
endpoint = 'https://us-central1-aiplatform.googleapis.com/v1/projects/myproject/locations/us-central1/publishers/google/models/multimodalembedding@001', make sure that the project that you specify in the URL is the project in which you have granted the Vertex AI user role to the connection's. service account.The
multimodalembedding@001model must be available in the location where you are creating the remote model. For more information, seeLocations.
Generate image embeddings
Generate image embeddings with theAI.GENERATE_EMBEDDING functionby using image data from an object table:
SELECT*FROMAI.GENERATE_EMBEDDING(MODEL`PROJECT_ID.DATASET_ID.MODEL_NAME`,TABLE`PROJECT_ID.DATASET_ID.TABLE_NAME`,STRUCT(OUTPUT_DIMENSIONALITYASoutput_dimensionality));
Replace the following:
PROJECT_ID: the project that contains the model or table.DATASET_ID: the dataset that contains the model or table.MODEL_NAME: the name of the remote model over amultimodalembedding@001model.TABLE_NAME: the name of the object table that contains the images to embed.OUTPUT_DIMENSIONALITY: anINT64value that specifies the number of dimensions to use when generating embeddings. Valid values are128,256,512, and1408. The default value is1408. For example, if you specify256 AS output_dimensionality, then theembeddingoutput column contains a 256-dimensional embedding for each input value.
Example
The following example shows how to create embeddings for the images intheimages object table:
SELECT*FROMAI.GENERATE_EMBEDDING(MODEL`mydataset.embedding_model`,TABLE`mydataset.images`,STRUCT(512ASoutput_dimensionality));
What's next
- Learn how touse text and image embeddings to perform a text-to-image semantic search.
- Learn how touse text embeddings for semantic search and retrieval-augmented generation (RAG).
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Last updated 2025-12-15 UTC.