Cache job constructed for a synchronous query.

gcloud/bigquery/query.py

@@ -50,6 +50,7 @@ def __init__(self, query, client):
         self._properties = {}
         self.query = query
         self._configuration = _SyncQueryConfiguration()
+        self._job = None
 
     @property
     def project(self):
@@ -134,9 +135,12 @@ def job(self):
         :returns: Job instance used to run the query (None until
                   ``jobReference`` property is set by the server).
         """
-        job_ref = self._properties.get('jobReference')
-        if job_ref is not None:
-            return QueryJob(job_ref['jobId'], self.query, self._client)
+        if self._job is None:
+            job_ref = self._properties.get('jobReference')
+            if job_ref is not None:
+                self._job = QueryJob(job_ref['jobId'], self.query,
+                                     self._client)
+        return self._job
 
     @property
     def page_token(self):

gcloud/bigquery/test_query.py

@@ -156,6 +156,8 @@ def test_job_w_jobid(self):
         self.assertEqual(job.query, self.QUERY)
         self.assertTrue(job._client is client)
         self.assertEqual(job.name, SERVER_GENERATED)
+        fetched_later = query.job
+        self.assertTrue(fetched_later is job)
 
     def test_schema(self):
         client = _Client(self.PROJECT)