diff --git a/swh/storage/cassandra/schema.py b/swh/storage/cassandra/schema.py
--- a/swh/storage/cassandra/schema.py
+++ b/swh/storage/cassandra/schema.py
@@ -186,6 +186,10 @@
     PRIMARY KEY (({main_algo}), {other_algos})
 );'''
 
+TABLES = ('content revision revision_parent release directory '
+          'directory_entry snapshot snapshot_branch origin_visit '
+          'origin tool_by_uuid tool object_count').split()
+
 HASH_ALGORITHMS = ['sha1', 'sha1_git', 'sha256', 'blake2s256']
 
 for main_algo in HASH_ALGORITHMS:
@@ -194,3 +198,5 @@
         other_algos=', '.join(
             [algo for algo in HASH_ALGORITHMS if algo != main_algo])
     ))
+
+    TABLES.append('content_by_%s' % main_algo)
diff --git a/swh/storage/tests/test_cassandra.py b/swh/storage/tests/test_cassandra.py
--- a/swh/storage/tests/test_cassandra.py
+++ b/swh/storage/tests/test_cassandra.py
@@ -13,6 +13,7 @@
 
 from swh.storage import get_storage
 from swh.storage.cassandra import create_keyspace
+from swh.storage.cassandra.schema import TABLES
 
 from swh.storage.tests.test_storage import TestStorage as _TestStorage
 from swh.storage.tests.test_storage import TestStorageGeneratedData \
@@ -127,16 +128,23 @@
             print(rf.message.query)
 
 
+@pytest.fixture(scope='session')
+def keyspace(cassandra_cluster):
+    (hosts, port) = cassandra_cluster
+    keyspace = os.urandom(10).hex()
+
+    create_keyspace(hosts, keyspace, port)
+
+    return keyspace
+
+
 # tests are executed using imported classes (TestStorage and
 # TestStorageGeneratedData) using overloaded swh_storage fixture
 # below
 
 @pytest.fixture
-def swh_storage(cassandra_cluster):
+def swh_storage(cassandra_cluster, keyspace):
     (hosts, port) = cassandra_cluster
-    keyspace = os.urandom(10).hex()
-
-    create_keyspace(hosts, keyspace, port)
 
     storage = get_storage(
         'cassandra',
@@ -153,8 +161,8 @@
 
     yield storage
 
-    storage._cql_runner._session.execute(
-        'DROP KEYSPACE "%s"' % keyspace)
+    for table in TABLES:
+        storage._cql_runner._session.execute('TRUNCATE TABLE "%s"' % table)
 
 
 @pytest.mark.cassandra