feat(bigquery): add bigquery_vector_search_brute_force sample to run exact brute-force vector search

Problem:
The BigQuery documentation (https://cloud.google.com/bigquery/docs/vector-search)
needs a standalone, tested Python code sample demonstrating how to
run exact brute-force vector search (region tag `bigquery_vector_search_brute_force`).

Solution:
- Add `vector_search_brute_force(project_id: str) -> None` in `bigquery/vector_search/bigquery_vector_search_brute_force.py`
  (Compute exact nearest-neighbor distances over embeddings using VECTOR_SEARCH with use_brute_force => TRUE.)
- Add unit tests (`bigquery/vector_search/bigquery_vector_search_brute_force_test.py`) covering both the success
  path and API error handling (`GoogleAPICallError`)

Author: iennae

bigquery/vector_search/bigquery_vector_search_brute_force.py

@@ -0,0 +1,97 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# [START bigquery_vector_search_brute_force]
+import sys
+
+from google.api_core import exceptions
+from google.cloud import bigquery
+
+
+def vector_search_brute_force(
+    project_id: str,
+) -> None:
+    """Runs an exact brute-force vector similarity search over BBC news embeddings.
+
+    Args:
+        project_id: Google Cloud project ID used to bill the query job
+            (for example, 'example-project').
+    """
+    client = bigquery.Client(project=project_id)
+    # Query the public BBC News dataset in bigquery-public-data
+    # (https://cloud.google.com/bigquery/public-data).
+    table_ref = "bigquery-public-data.bbc_news.fulltext"
+    # Pass a 768-dimensional query vector and enable use_brute_force for exact distance calculation.
+    category_filter = "tech"
+    query_embedding = [0.01] * 768
+    job_config = bigquery.QueryJobConfig(
+        query_parameters=[
+            bigquery.ScalarQueryParameter("category_filter", "STRING", category_filter),
+            bigquery.ArrayQueryParameter("query_embedding", "FLOAT64", query_embedding),
+        ]
+    )
+    sql = f"""
+        SELECT
+          base.title AS matched_title,
+          base.category AS matched_category,
+          distance
+        FROM VECTOR_SEARCH(
+          (
+            SELECT
+              title,
+              category,
+              body_embedded
+            FROM `{table_ref}`
+            WHERE category = @category_filter
+              AND ARRAY_LENGTH(body_embedded) = 768
+          ),
+          'body_embedded',
+          (SELECT @query_embedding AS query_embedding),
+          query_column_to_search => 'query_embedding',
+          top_k => 5,
+          distance_type => 'COSINE',
+          options => '{{"use_brute_force": true}}'
+        )
+        ORDER BY distance ASC, matched_title ASC;
+    """
+
+    try:
+        print(
+            f"Running brute-force vector search on {table_ref} (category={category_filter})"
+        )
+        query_job = client.query(sql, job_config=job_config)
+        rows = list(query_job.result())
+    except exceptions.NotFound as err:
+        print(
+            f"error: public embeddings table '{table_ref}' not found when querying "
+            f"from project '{project_id}': {err.message}",
+            file=sys.stderr,
+        )
+        return
+    except exceptions.GoogleAPICallError as err:
+        print(
+            f"error: failed to run brute-force vector search on '{table_ref}' in "
+            f"project '{project_id}': {err.message}",
+            file=sys.stderr,
+        )
+        return
+
+    print(f"Resource ID: {table_ref}")
+    print("Distance Type: COSINE")
+    print(f"Embedding Dimensions: {len(query_embedding)}")
+    print(f"Job ID: {query_job.job_id}")
+    print(f"Neighbors Returned: {len(rows)}")
+
+
+# [END bigquery_vector_search_brute_force]

bigquery/vector_search/bigquery_vector_search_brute_force_test.py

@@ -0,0 +1,56 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from unittest import mock
+
+import bigquery_vector_search_brute_force
+from google.api_core import exceptions
+import pytest
+
+
+def test_vector_search_brute_force_success(
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    with mock.patch("google.cloud.bigquery.Client") as mock_client_cls:
+        mock_client = mock_client_cls.return_value
+        mock_job = mock.MagicMock()
+        mock_job.job_id = "example-job-123"
+        mock_job.result.return_value = [mock.MagicMock() for _ in range(5)]
+        mock_client.query.return_value = mock_job
+
+        bigquery_vector_search_brute_force.vector_search_brute_force(
+            project_id="example-project",
+        )
+
+        mock_client.query.assert_called_once()
+        captured = capsys.readouterr()
+        assert "Resource ID: bigquery-public-data.bbc_news.fulltext" in captured.out
+        assert "Embedding Dimensions: 768" in captured.out
+        assert "Neighbors Returned: 5" in captured.out
+
+
+def test_vector_search_brute_force_error(
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    with mock.patch("google.cloud.bigquery.Client") as mock_client_cls:
+        mock_client = mock_client_cls.return_value
+        mock_client.query.side_effect = exceptions.NotFound("Table not found")
+
+        bigquery_vector_search_brute_force.vector_search_brute_force(
+            project_id="example-project",
+        )
+
+        captured = capsys.readouterr()
+        assert "error:" in captured.err
+        assert "bbc_news.fulltext" in captured.err

bigquery/vector_search/noxfile_config.py

@@ -0,0 +1,23 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+TEST_CONFIG_OVERRIDE = {
+    # You can opt out from the test for specific Python versions.
+    "ignored_versions": ["2.7", "3.7", "3.8", "3.9", "3.10", "3.11"],
+    # Enforce type hints on new samples.
+    "enforce_type_hints": True,
+    "gcloud_project_env": "GOOGLE_CLOUD_PROJECT",
+    "pip_version_override": None,
+    "envs": {},
+}

bigquery/vector_search/requirements-test.txt

@@ -0,0 +1 @@
+pytest==9.0.3; python_version >= "3.10"

bigquery/vector_search/requirements.txt

@@ -0,0 +1 @@
+google-cloud-bigquery==3.47.0