fix: make sure to fall back to old query path when query job is incom…

…plete (#941)

* fix: make sure to fall back to old query path when query job is incomplete (takes more than 10s)

* nit

* address comments

* add comment

* nit update

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

@@ -1268,20 +1268,22 @@ public com.google.api.services.bigquery.model.QueryResponse call() {
 
     long numRows;
     Schema schema;
-    if (results.getSchema() == null && results.getJobComplete()) {
-      JobId jobId = JobId.fromPb(results.getJobReference());
-      Job job = getJob(jobId, options);
-      TableResult tableResult = job.getQueryResults();
-      return tableResult;
-    } else {
-      schema = results.getSchema() == null ? null : Schema.fromPb(results.getSchema());
+    if (results.getJobComplete() && results.getSchema() != null) {
+      schema = Schema.fromPb(results.getSchema());
       if (results.getNumDmlAffectedRows() == null && results.getTotalRows() == null) {
         numRows = 0L;
       } else if (results.getNumDmlAffectedRows() != null) {
         numRows = results.getNumDmlAffectedRows();
       } else {
         numRows = results.getTotalRows().longValue();
       }
+    } else {
+      // Query is long running (> 10s) and hasn't completed yet, or query completed but didn't
+      // return the schema, fallback. Some operations don't return the schema and can be optimized
+      // here, but this is left as future work.
+      JobId jobId = JobId.fromPb(results.getJobReference());
+      Job job = getJob(jobId, options);
+      return job.getQueryResults();
     }
 
     if (results.getPageToken() != null) {

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

@@ -1955,6 +1955,63 @@ public void testFastQueryMultiplePages() throws InterruptedException {
     verify(bigqueryRpcMock).queryRpc(PROJECT, requestInfo.toPb());
   }
 
+  @Test
+  public void testFastQuerySlowDdl() throws InterruptedException {
+    // mock new fast query path response when running a query that takes more than 10s
+    JobId queryJob = JobId.of(PROJECT, JOB);
+    com.google.api.services.bigquery.model.QueryResponse queryResponsePb =
+        new com.google.api.services.bigquery.model.QueryResponse()
+            .setJobComplete(false) // false when query does not complete in 10s
+            .setJobReference(queryJob.toPb()) // backend sends back a jobReference
+            .setRows(ImmutableList.of(TABLE_ROW))
+            .setSchema(TABLE_SCHEMA.toPb());
+
+    // mock job response from backend
+    com.google.api.services.bigquery.model.Job responseJob =
+        new com.google.api.services.bigquery.model.Job()
+            .setConfiguration(QUERY_JOB_CONFIGURATION_FOR_QUERY.toPb())
+            .setJobReference(queryJob.toPb())
+            .setId(JOB)
+            .setStatus(new com.google.api.services.bigquery.model.JobStatus().setState("DONE"));
+
+    // mock old query path response when falling back
+    GetQueryResultsResponse queryResultsResponsePb =
+        new GetQueryResultsResponse()
+            .setJobReference(responseJob.getJobReference())
+            .setRows(ImmutableList.of(TABLE_ROW))
+            .setJobComplete(true)
+            .setTotalRows(BigInteger.valueOf(1L))
+            .setSchema(TABLE_SCHEMA.toPb());
+
+    QueryRequestInfo requestInfo = new QueryRequestInfo(QUERY_JOB_CONFIGURATION_FOR_QUERY);
+    QueryRequest requestPb = requestInfo.toPb();
+
+    when(bigqueryRpcMock.queryRpc(PROJECT, requestPb)).thenReturn(queryResponsePb);
+    responseJob.getConfiguration().getQuery().setDestinationTable(TABLE_ID.toPb());
+    when(bigqueryRpcMock.getJob(PROJECT, JOB, null, EMPTY_RPC_OPTIONS)).thenReturn(responseJob);
+    when(bigqueryRpcMock.getQueryResults(
+            PROJECT, JOB, null, BigQueryImpl.optionMap(Job.DEFAULT_QUERY_WAIT_OPTIONS)))
+        .thenReturn(queryResultsResponsePb);
+    when(bigqueryRpcMock.listTableData(PROJECT, DATASET, TABLE, EMPTY_RPC_OPTIONS))
+        .thenReturn(new TableDataList().setRows(ImmutableList.of(TABLE_ROW)).setTotalRows(1L));
+
+    bigquery = options.getService();
+    TableResult result = bigquery.query(QUERY_JOB_CONFIGURATION_FOR_QUERY);
+    assertThat(result.getSchema()).isEqualTo(TABLE_SCHEMA);
+    assertThat(result.getTotalRows()).isEqualTo(1);
+    for (FieldValueList row : result.getValues()) {
+      assertThat(row.get(0).getBooleanValue()).isFalse();
+      assertThat(row.get(1).getLongValue()).isEqualTo(1);
+    }
+
+    verify(bigqueryRpcMock).queryRpc(PROJECT, requestInfo.toPb());
+    verify(bigqueryRpcMock).getJob(PROJECT, JOB, null, EMPTY_RPC_OPTIONS);
+    verify(bigqueryRpcMock)
+        .getQueryResults(
+            PROJECT, JOB, null, BigQueryImpl.optionMap(Job.DEFAULT_QUERY_WAIT_OPTIONS));
+    verify(bigqueryRpcMock).listTableData(PROJECT, DATASET, TABLE, EMPTY_RPC_OPTIONS);
+  }
+
   @Test
   public void testQueryRequestCompletedOptions() throws InterruptedException {
     JobId queryJob = JobId.of(PROJECT, JOB);

google-cloud-bigquery/src/test/java/com/google/cloud/bigquery/it/ITBigQueryTest.java

@@ -1813,6 +1813,36 @@ public void testFastDDLQuery() throws InterruptedException {
     }
   }
 
+  @Test
+  public void testFastQuerySlowDDL() throws InterruptedException {
+    String tableName =
+        "test_table_fast_query_ddl_slow_" + UUID.randomUUID().toString().substring(0, 8);
+    // This query take more than 10s to run and should fall back on the old query path
+    String slowDdlQuery =
+        String.format(
+            "CREATE OR REPLACE TABLE %s AS SELECT unique_key, agency, complaint_type, descriptor, street_name, city, landmark FROM `bigquery-public-data.new_york.311_service_requests`",
+            tableName);
+    QueryJobConfiguration ddlConfig =
+        QueryJobConfiguration.newBuilder(slowDdlQuery)
+            .setDefaultDataset(DatasetId.of(DATASET))
+            .build();
+    TableResult result = bigquery.query(ddlConfig);
+    assertEquals(0, result.getTotalRows());
+    assertNotNull(result.getSchema());
+    // Verify correctness of table content
+    String sqlQuery = String.format("SELECT * FROM %s.%s", DATASET, tableName);
+    QueryJobConfiguration sqlConfig = QueryJobConfiguration.newBuilder(sqlQuery).build();
+    TableResult resultAfterDDL = bigquery.query(sqlConfig);
+    for (FieldValueList row : resultAfterDDL.getValues()) {
+      FieldValue unique_key = row.get(0);
+      assertEquals(unique_key, row.get("unique_key"));
+      FieldValue agency = row.get(1);
+      assertEquals(agency, row.get("agency"));
+      FieldValue complaint_type = row.get(2);
+      assertEquals(complaint_type, row.get("complaint_type"));
+    }
+  }
+
   @Test
   public void testFastQueryHTTPException() throws InterruptedException {
     String queryInvalid =