The AI.EMBED function
This document describes the AI.EMBED
function, which lets you create embeddings
from text or image data in BigQuery.
For example, the following query creates an embedding for a piece of text:
SELECT
AI
.
EMBED
(
"Some text to embed!"
,
endpoint
=
>
'text-embedding-005'
);
The function works by sending a request to a stable Vertex AI embedding model , and then returning that model's response. The function incurs charges in Vertex AI each time it's called.
Embeddings
Embeddings are high-dimensional numerical vectors that represent a given entity. Machine learning (ML) models use embeddings to encode semantics about entities to make it easier to reason about and compare them. If two entities are semantically similar, then their respective embeddings are located near each other in the embedding vector space.
Embeddings help you perform the following tasks:
- Semantic search: search entities ranked by semantic similarity.
- Recommendation: return entities with attributes similar to a given entity.
- Classification: return the class of entities whose attributes are similar to the given entity.
- Clustering: cluster entities whose attributes are similar to a given entity.
- Outlier detection: return entities whose attributes are least related to the given entity.
Input
Using the AI.EMBED
function, you can use the following types
of input:
- Text data.
- Image data represented by
ObjectRefRuntimevalues.ObjectRefRuntimevalues are generated by theOBJ.GET_ACCESS_URLfunction . You can useObjectRefvalues from standard tables as input to theOBJ.GET_ACCESS_URLfunction. ( Preview )
When you analyze image data, the content must be in one of the supported image
formats that are described in the Gemini API model mimeType
parameter
.
Syntax
Text embedding
AI . EMBED ( [ content => ] ' content ' , endpoint => ' endpoint ' [ , task_type => ' task_type ' ] [ , title => ' title ' ] [ , model_params => model_params ] [ , connection_id => ' connection ' ] )
Arguments
AI.EMBED
takes the following arguments:
-
content: aSTRINGvalue that provides the text to embed.The
contentvalue can be a string literal, the name of a table column, or the output of an expression that evaluates to a string. -
endpoint: aSTRINGvalue that specifies a supported Vertex AI text embedding model endpoint to use for the text embedding model. The endpoint value that you specify must include the model version, for exampletext-embedding-005. If you specify the model name rather than a URL, BigQuery ML automatically identifies the model and uses the model's full endpoint. -
task_type: aSTRINGliteral that specifies the intended downstream application to help the model produce better quality embeddings. Thetask_typeargument accepts the following values:-
RETRIEVAL_QUERY: specifies that the given text is a query in a search or retrieval setting. -
RETRIEVAL_DOCUMENT: specifies that the given text is a document in a search or retrieval setting. -
SEMANTIC_SIMILARITY: specifies that the given text will be used for Semantic Textual Similarity (STS). -
CLASSIFICATION: specifies that the embeddings will be used for classification. -
CLUSTERING: specifies that the embeddings will be used for clustering. -
QUESTION_ANSWERING: specifies that the embeddings will be used for question answering. -
FACT_VERIFICATION: specifies that the embeddings will be used for fact verification. -
CODE_RETRIEVAL_QUERY: specifies that the embeddings will be used for code retrieval.
-
-
title: ASTRINGvalue that specifies the document title, which the model uses to improve embedding quality. You can only use this parameter if you specifyRETRIEVAL_DOCUMENTfor thetask_typevalue. -
model_params: aJSONliteral that provides additional parameters to the model. You can use any of theparametersobject fields. One of these fields,outputDimensionality, lets you specify the number of dimensions to use when generating embeddings. For example, if you specify256for theoutputDimensionalityfield , then the model returns 256 embeddings for each input value. -
connection_id: aSTRINGvalue specifying the connection to use to communicate with the model, in the formatPROJECT_ID.LOCATION.CONNECTION_ID. For example,myproject.us.myconnection.For user-initiated queries, the
CONNECTIONargument is optional. When a user initiates a query, BigQuery ML uses the credentials of the user who submitted the query to run it.If your query job is expected to run for 48 hours or longer, you should use the
CONNECTIONargument to run the query using a service account.Replace the following:
-
PROJECT_ID: the project ID of the project that contains the connection. -
LOCATION: the location used by the connection. The connection must be in the same region in which the query is run. -
CONNECTION_ID: the connection ID—for example,myconnection.You can get this value by viewing the connection details in the Google Cloud console and copying the value in the last section of the fully qualified connection ID that is shown in Connection ID . For example,
projects/myproject/locations/connection_location/connections/ myconnection.
You need to grant the Vertex AI User role to the connection's service account in the project where you run the function.
-
Multimodal embedding
AI . EMBED ( [ content => ] ' content ' , connection_id => ' connection ' , endpoint => ' endpoint ' [ , model_params => model_params ] )
Arguments
AI.EMBED
takes the following arguments:
-
content: aSTRING,ObjectRef, orObjectRefRuntimevalue that provides the data to embed.- For text embeddings, you can specify one of the following:
- A string literal.
- The name of a
STRINGcolumn. - The output of an expression that evaluates to a string.
- For image content embeddings, you can specify one of the following:
- The name of an
ObjectRefcolumn. - An
ObjectRefvalue generated by a combination of theOBJ.FETCH_METADATAandOBJ.MAKE_REFfunctions. For exampleSELECT OBJ.FETCH_METADATA(OBJ.MAKE_REF("gs://mybucket/path/to/file.jpg", "us.connection1"));. - An
ObjectRefRuntimevalue generated by theOBJ.GET_ACCESS_URLfunction .
- The name of an
ObjectRefvalues must have thedetails.gcs_metadata.content_typeelements of the JSON value populated.ObjectRefRuntimevalues must have theaccess_url.read_urlanddetails.gcs_metadata.content_typeelements of the JSON value populated. - For text embeddings, you can specify one of the following:
-
connection_id: aSTRINGvalue specifying the connection to use to communicate with the model, in the formatPROJECT_ID.LOCATION.CONNECTION_ID. For example,myproject.us.myconnection.Replace the following:
-
PROJECT_ID: the project ID of the project that contains the connection. -
LOCATION: the location used by the connection. The connection must be in the same region in which the query is run. -
CONNECTION_ID: the connection ID—for example,myconnection.You can get this value by viewing the connection details in the Google Cloud console and copying the value in the last section of the fully qualified connection ID that is shown in Connection ID . For example,
projects/myproject/locations/connection_location/connections/ myconnection.
You need to grant the Vertex AI User role to the connection's service account in the project where you run the function.
-
-
endpoint: aSTRINGvalue that specifies a supported Vertex AI multimodal embedding model endpoint to use for the multimodal embedding model. The endpoint value that you specify must include the model version, for examplemultimodalembedding@001. If you specify the model name rather than a URL, BigQuery ML automatically identifies the model and uses the model's full endpoint. -
model_params: aJSONliteral that provides additional parameters to the model. Only thedimensionfield is supported. You can use thedimensionfield to specify the number of dimensions to use when generating embeddings. For example, if you specify256for thedimensionfield , then the model returns 256 embeddings for each input value.
Output
AI.EMBED
returns a STRUCT
value for each row in the table. The struct
contains the following fields:
-
result: anARRAY<FLOAT64>value containing the generated embeddings. -
status: aSTRINGvalue that contains the API response status for the corresponding row. This value is empty if the operation was successful.
Examples
text embedding
The following example shows how to embed a string literal:
SELECT
AI
.
EMBED
(
'A piece of text to embed'
,
endpoint
=
>
'text-embedding-005'
).
result
AS
embedding
;
If you need to reuse embeddings of the same data across many queries, you should save the results to table. The following example generates 768-dimensional embeddings for publicly available BBC news articles and writes the results to a table:
CREATE
OR
REPLACE
TABLE
mydataset
.
bbc_news_embeddings
AS
SELECT
title
,
body
,
AI
.
EMBED
(
body
,
endpoint
=
>
'text-embedding-005'
,
model_params
=
>
JSON
'{"outputDimensionality": 768}'
).
result
AS
embedding
FROM
`bigquery-public-data.bbc_news.fulltext`
;
The following example queries the table that you just created for the
five articles that are most related to the topic "latest news in tech".
It calls the VECTOR_SEARCH
function and uses AI.EMBED
to create
an embedding to pass to the function as the search query.
SELECT
base
.
title
,
base
.
body
FROM
VECTOR_SEARCH
(
TABLE
mydataset
.
bbc_news_embeddings
,
# The name of the column that contains the embedding
'embedding'
,
# The embedding to search
(
SELECT
AI
.
EMBED
(
'latest news in tech'
,
endpoint
=
>
'text-embedding-005'
).
result
),
top_k
=
>
5
);
multimodal embedding
The following query creates an external table from images of pet products stored in a publicly available Cloud Storage bucket. Then, it generates embeddings for two of the images:
# Create a dataset CREATE SCHEMA IF NOT EXISTS cymbal_pets ; # Create an object table CREATE OR REPLACE EXTERNAL TABLE cymbal_pets . product_images WITH CONNECTION DEFAULT OPTIONS ( object_metadata = 'SIMPLE' , uris = [ 'gs://cloud-samples-data/bigquery/tutorials/cymbal-pets/images/*.png' ] ); SELECT ref . uri , STRING ( OBJ . GET_ACCESS_URL ( ref , 'r' ). access_urls . read_url ) AS signed_url , AI . EMBED ( ( OBJ . GET_ACCESS_URL ( ref , 'r' )), connection_id => 'us.example_connection' , endpoint => 'multimodalembedding@001' ) AS embedding FROM `cymbal_pets.product_images` LIMIT 2 ;
Locations
You can run AI.EMBED
in all of the locations
that support Vertex AI embedding models, and also in the US
and EU
multi-regions.
Quotas
See Vertex AI and Cloud AI service functions quotas and limits .
What's next
- For more information about using Vertex AI models to generate text and embeddings, see Generative AI overview .
- For more information about using Cloud AI APIs to perform AI tasks, see AI application overview .

