diff --git a/swh/storage/tests/test_storage.py b/swh/storage/tests/test_storage.py
--- a/swh/storage/tests/test_storage.py
+++ b/swh/storage/tests/test_storage.py
@@ -34,11 +34,6 @@
 class StorageTestDbFixture(StorageTestFixture):
     def setUp(self):
         super().setUp()
-
-        db = self.test_db[self.TEST_DB_NAME]
-        self.conn = db.conn
-        self.cursor = db.cursor
-
         self.maxDiff = None
 
     def tearDown(self):
@@ -711,13 +706,15 @@
 
         if hasattr(self.storage, 'objstorage'):
             self.assertIn(cont['sha1'], self.storage.objstorage)
-        self.cursor.execute('SELECT sha1, sha1_git, sha256, length, status'
-                            ' FROM content WHERE sha1 = %s',
-                            (cont['sha1'],))
-        datum = self.cursor.fetchone()
+
+        with self.db_transaction() as (_, cur):
+            cur.execute('SELECT sha1, sha1_git, sha256, length, status'
+                        ' FROM content WHERE sha1 = %s',
+                        (cont['sha1'],))
+            datum = cur.fetchone()
+
         self.assertEqual(
-            (datum[0].tobytes(), datum[1].tobytes(), datum[2].tobytes(),
-             datum[3], datum[4]),
+            datum,
             (cont['sha1'], cont['sha1_git'], cont['sha256'],
              cont['length'], 'visible'))
 
@@ -802,13 +799,15 @@
 
         if hasattr(self.storage, 'objstorage'):
             self.assertNotIn(cont['sha1'], self.storage.objstorage)
-        self.cursor.execute('SELECT sha1, sha1_git, sha256, length, status'
-                            ' FROM content WHERE sha1 = %s',
-                            (cont['sha1'],))
-        datum = self.cursor.fetchone()
+
+        with self.db_transaction() as (_, cur):
+            cur.execute('SELECT sha1, sha1_git, sha256, length, status'
+                        ' FROM content WHERE sha1 = %s',
+                        (cont['sha1'],))
+            datum = cur.fetchone()
+
         self.assertEqual(
-            (datum[0].tobytes(), datum[1].tobytes(), datum[2].tobytes(),
-             datum[3], datum[4]),
+            datum,
             (cont['sha1'], cont['sha1_git'], cont['sha256'],
              cont['length'], 'visible'))
 
@@ -844,26 +843,23 @@
             'skipped_content:add': 2,
         })
 
-        self.cursor.execute('SELECT sha1, sha1_git, sha256, blake2s256, '
-                            'length, status, reason '
-                            'FROM skipped_content ORDER BY sha1_git')
+        with self.db_transaction() as (_, cur):
+            cur.execute('SELECT sha1, sha1_git, sha256, blake2s256, '
+                        'length, status, reason '
+                        'FROM skipped_content ORDER BY sha1_git')
 
-        datums = self.cursor.fetchall()
+            data = cur.fetchall()
 
-        self.assertEqual(2, len(datums))
-        datum = datums[0]
+        self.assertEqual(2, len(data))
         self.assertEqual(
-            (datum[0].tobytes(), datum[1].tobytes(), datum[2].tobytes(),
-             datum[3].tobytes(), datum[4], datum[5], datum[6]),
+            data[0],
             (cont['sha1'], cont['sha1_git'], cont['sha256'],
              cont['blake2s256'], cont['length'], 'absent',
              'Content too long')
         )
 
-        datum2 = datums[1]
         self.assertEqual(
-            (datum2[0].tobytes(), datum2[1].tobytes(), datum2[2].tobytes(),
-             datum2[3], datum2[4], datum2[5], datum2[6]),
+            data[1],
             (cont2['sha1'], cont2['sha1_git'], cont2['sha256'],
              cont2['blake2s256'], cont2['length'], 'absent',
              'Content too long')
@@ -4056,18 +4052,13 @@
         results = queue.Queue()
 
         def thread():
-            db = None
             try:
-                db = self.storage.get_db()
-                with db.transaction() as cur:
+                with self.db_transaction() as (db, cur):
                     ret = self.storage.content_add([self.cont], db=db,
                                                    cur=cur)
                 results.put((threading.get_ident(), 'data', ret))
             except Exception as e:
                 results.put((threading.get_ident(), 'exc', e))
-            finally:
-                if db:
-                    self.storage.put_db(db)
 
         t1 = threading.Thread(target=thread)
         t2 = threading.Thread(target=thread)
@@ -4116,7 +4107,7 @@
 
         self.storage.content_update([cont], keys=['sha1_git'])
 
-        with self.storage.get_db().transaction() as cur:
+        with self.db_transaction() as (_, cur):
             cur.execute('SELECT sha1, sha1_git, sha256, length, status'
                         ' FROM content WHERE sha1 = %s',
                         (cont['sha1'],))
@@ -4131,7 +4122,7 @@
     def test_content_update_with_new_cols(self):
         self.storage.journal_writer = None  # TODO, not supported
 
-        with self.storage.get_db().transaction() as cur:
+        with self.db_transaction() as (db, cur):
             cur.execute("""alter table content
                            add column test text default null,
                            add column test2 text default null""")
@@ -4142,10 +4133,11 @@
         cont['test2'] = 'value-2'
 
         self.storage.content_update([cont], keys=['test', 'test2'])
-        with self.storage.get_db().transaction() as cur:
+        with self.db_transaction() as (_, cur):
             cur.execute(
-                'SELECT sha1, sha1_git, sha256, length, status, test, test2'
-                ' FROM content WHERE sha1 = %s',
+                '''SELECT sha1, sha1_git, sha256, length, status,
+                   test, test2
+                   FROM content WHERE sha1 = %s''',
                 (cont['sha1'],))
 
             datum = cur.fetchone()
@@ -4156,6 +4148,6 @@
             (cont['sha1'], cont['sha1_git'], cont['sha256'],
              cont['length'], 'visible', cont['test'], cont['test2']))
 
-        with self.storage.get_db().transaction() as cur:
+        with self.db_transaction() as (_, cur):
             cur.execute("""alter table content drop column test,
-                           drop column test2""")
+                                               drop column test2""")