diff --git a/swh/loader/git/storage/db.py b/swh/loader/git/storage/db.py
index 7f603aa..4bea13d 100644
--- a/swh/loader/git/storage/db.py
+++ b/swh/loader/git/storage/db.py
@@ -1,91 +1,93 @@
 # Copyright (C) 2015  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import psycopg2
 
 
 connect = psycopg2.connect
 
 
 def execute(cur, query_params, trace=None):
     """Execute the query_params.
     query_params is expected to be either:
     - a sql query (string)
     - a tuple (sql query, params)
     """
-    if trace:
-        print("query: ", cur.mogrify(*query_params).decode())
     if isinstance(query_params, str):
+        if trace:
+            print("query: '%s'" % query_params)
         cur.execute(query_params)
     else:
+        if trace:
+            print("query: ", cur.mogrify(*query_params).decode())
         cur.execute(*query_params)
 
 
 def copy_from(cur, file, table):
     """Copy the content of a file to the db in the table table.
     """
     cur.copy_from(file, table)
 
 
 def insert(db_conn, query_params, trace=None):
     """Execute an insertion and returns the identifier.
     Expect an insert query with the right returning clause.
     No check is done.
     """
     with db_conn.cursor() as cur:
         execute(cur, query_params, trace)
         result = cur.fetchone()
         return result[0]
 
 
 def query_execute(db_conn, query_params, trace=None):
     """Execute one query.
     Type of sql queries: insert, delete, drop, create...
     query_params is expected to be either:
     - a sql query (string)
     - a tuple (sql query, params)
     """
     with db_conn.cursor() as cur:
         return execute(cur, query_params, trace)
 
 
 def queries_execute(db_conn, queries_params, trace=None):
     """Execute multiple queries without any result expected.
     Type of sql queries: insert, delete, drop, create...
     query_params is expected to be a list of mixed:
     - sql query (string)
     - tuple (sql query, params)
     """
     with db_conn.cursor() as cur:
         for query_params in queries_params:
             execute(cur, query_params, trace)
 
 
 def query_fetchone(db_conn, query_params, trace=None):
     """Execute sql query which returns one result.
     query_params is expected to be either:
     - a sql query (string)
     - a tuple (sql query, params)
     """
     with db_conn.cursor() as cur:
         return fetchone(cur, query_params, trace)
 
 
 def fetchone(cur, query_params, trace=None):
     """Execute sql query and returns one result.
     """
     execute(cur, query_params, trace)
     return cur.fetchone()
 
 
 def query_fetch(db_conn, query_params, trace=None):
     """Execute sql query which returns results.
     query_params is expected to be either:
     - a sql query (string)
     - a tuple (sql query, params)
     """
     with db_conn.cursor() as cur:
         execute(cur, query_params, trace)
         return cur.fetchall()