fix(bigquery): default Arrow pagination stream location to US instead of global

java-bigquery/google-cloud-bigquery/src/main/java/com/google/cloud/bigquery/BigQueryImpl.java

@@ -379,18 +379,19 @@ public Page<FieldValueList> getNextPage() {
       List<FieldValueList> rowBatch = new ArrayList<>((int) Math.min(pageSize, 10000L));
 
       try {
-        // Resolve job location in order: JobId location -> BigQueryOptions location -> "global"
+        // Resolve job location in order: JobId location -> BigQueryOptions location -> "US"
         // default.
         // The Storage Read API stream resource name requires a location component (e.g.
         // projects/{project}/locations/{location}/jobs/{job}/streams/_default). If no specific
-        // location was provided on the job or service options, defaulting to "global" allows
-        // queries created without an explicit location to still stream results without failing.
+        // location was provided on the job or service options, defaulting to "US" (the standard
+        // BigQuery default multi-region) allows queries created without an explicit location
+        // to stream results from default datasets without failing.
         String location = jobId.getLocation();
         if (location == null) {
           location = serviceOptions.getLocation();
         }
         if (location == null) {
-          location = "global";
+          location = "US";
         }
 
         if (streamIterator == null) {
@@ -2919,12 +2920,13 @@ && getOptions().getOpenTelemetryTracer() != null) {
           if (jobLocation == null) {
             jobLocation = getOptions().getLocation();
           }
-          if (jobLocation != null) {
-            streamName =
-                String.format(
-                    "projects/%s/locations/%s/jobs/%s/streams/_default",
-                    jobProject, jobLocation, actualJobId.getJob());
+          if (jobLocation == null) {
+            jobLocation = "US";
           }
+          streamName =
+              String.format(
+                  "projects/%s/locations/%s/jobs/%s/streams/_default",
+                  jobProject, jobLocation, actualJobId.getJob());
         }
 
         BigQueryReadClient client = null;

java-bigquery/google-cloud-bigquery/src/test/java/com/google/cloud/bigquery/ArrowQueryPageFetcherTest.java

@@ -289,8 +289,8 @@ void testGetNextPage_respectsMaxResults() throws IOException {
   }
 
   @Test
-  void testGetNextPage_missingLocationDefaultsToGlobal() throws IOException {
-    byte[] batchBytes = createBatchBytes(ImmutableList.of(10L));
+  void testGetNextPage_missingLocationDefaultsToUS() throws IOException {
+    byte[] batchBytes = createBatchBytes(ImmutableList.of(1L));
     ReadRowsResponse response =
         ReadRowsResponse.newBuilder()
             .setArrowRecordBatch(
@@ -331,7 +331,7 @@ void testGetNextPage_missingLocationDefaultsToGlobal() throws IOException {
     Page<FieldValueList> page = fetcher.getNextPage();
     assertNotNull(page);
     assertEquals(
-        "projects/" + PROJECT + "/locations/global/jobs/" + JOB + "/streams/_default",
+        "projects/" + PROJECT + "/locations/US/jobs/" + JOB + "/streams/_default",
         requestCapture.getValue().getReadStream());
   }
 

java-bigquery/google-cloud-bigquery/src/test/java/com/google/cloud/bigquery/BigQueryImplTest.java

@@ -2954,6 +2954,65 @@ void testQueryArrowDefaultsToJobCreationOptional() throws IOException, Interrupt
     assertEquals("ARROW", requestPb.getQueryResultsFormat());
   }
 
+  @Test
+  void testQueryArrowDefaultsToUSLocationWhenUnspecified() throws Exception {
+    org.apache.arrow.vector.types.pojo.Schema arrowSchema =
+        new org.apache.arrow.vector.types.pojo.Schema(
+            ImmutableList.of(
+                org.apache.arrow.vector.types.pojo.Field.nullable(
+                    "id", new ArrowType.Int(64, true))));
+
+    byte[] schemaBytes;
+    try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
+      MessageSerializer.serialize(new WriteChannel(Channels.newChannel(out)), arrowSchema);
+      schemaBytes = out.toByteArray();
+    }
+
+    QueryJobConfiguration config =
+        QueryJobConfiguration.newBuilder("SELECT 1")
+            .setQueryResultsFormat(QueryResultsFormat.ARROW)
+            .build();
+    com.google.api.services.bigquery.model.JobReference jobRef =
+        new com.google.api.services.bigquery.model.JobReference()
+            .setProjectId(PROJECT)
+            .setJobId(JOB); // No location set
+    com.google.api.services.bigquery.model.QueryResponse queryResponsePb =
+        new com.google.api.services.bigquery.model.QueryResponse()
+            .setJobReference(jobRef)
+            .setJobComplete(true)
+            .setTotalRows(BigInteger.ONE)
+            .setArrowSchema(
+                new com.google.api.services.bigquery.model.ArrowSchema()
+                    .setSerializedSchema(BaseEncoding.base64().encode(schemaBytes)));
+
+    BigQueryReadClient mockReadClient =
+        mock(BigQueryReadClient.class, withSettings().withoutAnnotations());
+    @SuppressWarnings("unchecked")
+    ServerStreamingCallable<ReadRowsRequest, ReadRowsResponse> mockCallable =
+        mock(ServerStreamingCallable.class, withSettings().withoutAnnotations());
+    @SuppressWarnings("unchecked")
+    ServerStream<ReadRowsResponse> mockServerStream =
+        mock(ServerStream.class, withSettings().withoutAnnotations());
+    ArgumentCaptor<ReadRowsRequest> requestCapture = ArgumentCaptor.forClass(ReadRowsRequest.class);
+    when(mockCallable.call(requestCapture.capture())).thenReturn(mockServerStream);
+    when(mockServerStream.iterator()).thenReturn(Collections.emptyIterator());
+    when(mockReadClient.readRowsCallable()).thenReturn(mockCallable);
+
+    when(bigqueryRpcMock.queryRpcSkipExceptionTranslation(eq(PROJECT), any(QueryRequest.class)))
+        .thenReturn(queryResponsePb);
+
+    bigquery = options.getService();
+    ((BigQueryImpl) bigquery).setBigQueryReadClient(mockReadClient);
+
+    ArrowQueryResult result = bigquery.queryArrow(config);
+    assertNotNull(result);
+    result.iterator().hasNext();
+
+    assertEquals(
+        "projects/" + PROJECT + "/locations/US/jobs/" + JOB + "/streams/_default",
+        requestCapture.getValue().getReadStream());
+  }
+
   @Test
   void testQueryWithArrowFormatSlowPathFallback() throws Exception {
     JobId queryJob = JobId.of(PROJECT, JOB).toBuilder().setLocation(LOCATION).build();