diff --git a/src/backend/postgres/test/test-db.c b/src/backend/postgres/test/test-db.c
index 4421bbeeba..d876436d84 100644
--- a/src/backend/postgres/test/test-db.c
+++ b/src/backend/postgres/test/test-db.c
@@ -20,7 +20,7 @@ save_xml_file (GNCSession *session, const char *filename_base)
   char cwd[1024];
   char *filename;
 
-  g_return_if_fail (session && filename);
+  g_return_if_fail (session && filename_base);
 
   getcwd (cwd, sizeof (cwd));
 
@@ -51,66 +51,206 @@ save_xml_files (GNCSession *session_1, GNCSession *session_2)
   save_xml_file (session_2, "test_file_2");
 }
 
-static void
-run_test (void)
+static char *
+db_file_url (const char *db_name, const char *mode)
+{
+  g_return_val_if_fail (db_name && mode, NULL);
+
+  return g_strdup_printf ("postgres://localhost:7777/%s?mode=%s",
+                          db_name, mode);
+}
+
+static gboolean
+save_db_file (GNCSession *session, const char *db_name, const char *mode)
 {
-  GNCSession *session;
-  GNCSession *session_db;
   GNCBackendError io_err;
   char *filename;
-  gboolean ok;
 
-  session = get_random_session ();
+  g_return_val_if_fail (session && db_name && mode, FALSE);
 
-  add_random_transactions_to_session (session,
-                                      get_random_int_in_range (1, 20));
-
-  filename = g_strdup ("postgres://localhost:7777/gnc_test?mode=single-file");
+  filename = db_file_url (db_name, mode);
 
   gnc_session_begin (session, filename, FALSE, TRUE);
   io_err = gnc_session_get_error (session);
-  if (!do_test (io_err == ERR_BACKEND_NO_ERR, "Beginning gnc_test"))
-    return;
+  if (!do_test_args (io_err == ERR_BACKEND_NO_ERR,
+                     "Beginning db session",
+                     __FILE__, __LINE__,
+                     "can't begin session for %s in mode %s",
+                     db_name, mode))
+    return FALSE;
 
   gnc_session_save (session);
   io_err = gnc_session_get_error (session);
-  if (!do_test (io_err == ERR_BACKEND_NO_ERR, "Saving gnc_test"))
-    return;
+  if (!do_test_args (io_err == ERR_BACKEND_NO_ERR,
+                     "Saving db session",
+                     __FILE__, __LINE__,
+                     "can't save session for %s in mode %s",
+                     db_name, mode))
+    return FALSE;
 
   gnc_session_end (session);
   io_err = gnc_session_get_error (session);
-  if (!do_test (io_err == ERR_BACKEND_NO_ERR, "Ending gnc_test"))
-    return;
+  if (!do_test_args (io_err == ERR_BACKEND_NO_ERR,
+                     "Ending db session",
+                     __FILE__, __LINE__,
+                     "can't end session for %s in mode %s",
+                     db_name, mode))
+    return FALSE;
 
-  if (!do_test (gnc_session_get_url (session) == NULL, "session url not NULL"))
-    return;
+  do_test (gnc_session_get_url (session) == NULL, "session url not NULL");
 
-  session_db = gnc_session_new ();
+  g_free (filename);
 
-  gnc_session_begin (session_db, filename, FALSE, FALSE);
-  io_err = gnc_session_get_error (session_db);
-  if (!do_test (io_err == ERR_BACKEND_NO_ERR, "Beginning gnc_test load"))
-    return;
+  return TRUE;
+}
 
-  gnc_session_load (session_db);
-  io_err = gnc_session_get_error (session_db);
-  if (!do_test (io_err == ERR_BACKEND_NO_ERR, "Loading gnc_test"))
-    return;
+static gboolean
+load_db_file (GNCSession *session, const char *db_name, const char *mode)
+{
+  GNCBackendError io_err;
+  char *filename;
 
-  gnc_session_end (session_db);
-  io_err = gnc_session_get_error (session_db);
-  if (!do_test (io_err == ERR_BACKEND_NO_ERR, "Ending gnc_test load"))
-    return;
+  g_return_val_if_fail (session && db_name && mode, FALSE);
+
+  filename = db_file_url (db_name, mode);
+
+  gnc_session_begin (session, filename, FALSE, FALSE);
+  io_err = gnc_session_get_error (session);
+  if (!do_test_args (io_err == ERR_BACKEND_NO_ERR,
+                     "Beginning db session",
+                     __FILE__, __LINE__,
+                     "can't begin session for %s in mode %s",
+                     db_name, mode))
+    return FALSE;
+
+  gnc_session_load (session);
+  io_err = gnc_session_get_error (session);
+  if (!do_test_args (io_err == ERR_BACKEND_NO_ERR,
+                     "Loading db session",
+                     __FILE__, __LINE__,
+                     "can't load session for %s in mode %s",
+                     db_name, mode))
+    return FALSE;
+
+  gnc_session_end (session);
+  io_err = gnc_session_get_error (session);
+  if (!do_test_args (io_err == ERR_BACKEND_NO_ERR,
+                     "Ending db session",
+                     __FILE__, __LINE__,
+                     "can't end session for %s in mode %s",
+                     db_name, mode))
+    return FALSE;
+
+  do_test (gnc_session_get_url (session) == NULL, "session url not NULL");
+
+  g_free (filename);
+
+  return TRUE;
+}
+
+static gboolean
+test_access (const char *db_name, const char *mode, gboolean multi_user)
+{
+  GNCBackendError io_err;
+  GNCSession *session_1;
+  GNCSession *session_2;
+  char *filename;
+
+  g_return_val_if_fail (db_name && mode, FALSE);
+
+  filename = db_file_url (db_name, mode);
+
+  session_1 = gnc_session_new ();
+
+  gnc_session_begin (session_1, filename, FALSE, FALSE);
+  io_err = gnc_session_get_error (session_1);
+  if (!do_test_args (io_err == ERR_BACKEND_NO_ERR,
+                     "Beginning db session",
+                     __FILE__, __LINE__,
+                     "can't begin session for %s in mode %s",
+                     db_name, mode))
+    return FALSE;
+
+  session_2 = gnc_session_new ();
+
+  gnc_session_begin (session_1, filename, FALSE, FALSE);
+  io_err = gnc_session_get_error (session_1);
+
+  if (multi_user)
+  {
+    if (!do_test_args (io_err == ERR_BACKEND_NO_ERR,
+                       "Beginning second multi-user db session",
+                       __FILE__, __LINE__,
+                       "can't begin second session for %s in mode %s",
+                       db_name, mode))
+      return FALSE;
+  }
+  else
+  {
+    if (!do_test_args (io_err != ERR_BACKEND_NO_ERR,
+                       "Beginning second single-user db session",
+                       __FILE__, __LINE__,
+                       "began second session for %s in mode %s",
+                       db_name, mode))
+      return FALSE;
+  }
+
+  gnc_session_destroy (session_1);
+  gnc_session_destroy (session_2);
+
+  return TRUE;
+}
+
+static gboolean
+test_mode (const char *db_name, const char *mode,
+           gboolean updates, gboolean multi_user)
+{
+  GNCSession *session;
+  GNCSession *session_db;
+  gboolean ok;
+
+  session = get_random_session ();
+
+  add_random_transactions_to_session (session,
+                                      get_random_int_in_range (1, 20));
+
+  if (!save_db_file (session, db_name, mode))
+    return FALSE;
+
+  session_db = gnc_session_new ();
+
+  if (!load_db_file (session_db, db_name, mode))
+    return FALSE;
 
   ok = gnc_book_equal (gnc_session_get_book (session),
                        gnc_session_get_book (session_db));
 
-  do_test (ok, "Books not equal");
+  do_test_args (ok, "Books equal", __FILE__, __LINE__,
+                "Books not equal for session %s in mode %s",
+                db_name, mode);
 
   if (!ok)
+  {
     save_xml_files (session, session_db);
+    return FALSE;
+  }
 
-  g_free (filename);
+  ok = test_access (db_name, mode, multi_user);
+
+  gnc_session_destroy (session);
+  gnc_session_destroy (session_db);
+
+  return ok;
+}
+
+static void
+run_test (void)
+{
+  if (!test_mode ("single_file", "single-file", FALSE, FALSE))
+    return;
+
+  if (!test_mode ("single_update", "single-update", FALSE, FALSE))
+    return;
 }
 
 static void