From 60a3552f05a884083d52869a013f5975eb12a115 Mon Sep 17 00:00:00 2001
From: xadrianzetx <xadrianzetx@gmail.com>
Date: Sun, 17 Sep 2023 10:56:17 +0200
Subject: [PATCH] Use `metric_names` attribute instead of querying the storage
 directly

---
 optuna/study/_dataframe.py            | 5 +----
 optuna/study/study.py                 | 4 +---
 optuna/visualization/_pareto_front.py | 5 +----
 3 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/optuna/study/_dataframe.py b/optuna/study/_dataframe.py
index b311443055..84131526e9 100644
--- a/optuna/study/_dataframe.py
+++ b/optuna/study/_dataframe.py
@@ -8,7 +8,6 @@
 
 import optuna
 from optuna._imports import try_import
-from optuna.study.study import _SYSTEM_ATTR_METRIC_NAMES
 from optuna.trial._state import TrialState
 
 
@@ -41,9 +40,7 @@ def _create_records_and_aggregate_column(
     column_agg: DefaultDict[str, Set] = collections.defaultdict(set)
     non_nested_attr = ""
 
-    metric_names = study._storage.get_study_system_attrs(study._study_id).get(
-        _SYSTEM_ATTR_METRIC_NAMES
-    )
+    metric_names = study.metric_names
 
     records = []
     for trial in study.get_trials(deepcopy=False):
diff --git a/optuna/study/study.py b/optuna/study/study.py
index 07140c14ce..eae8fd0993 100644
--- a/optuna/study/study.py
+++ b/optuna/study/study.py
@@ -1088,9 +1088,7 @@ def _log_completed_trial(self, trial: trial_module.FrozenTrial) -> None:
         if not _logger.isEnabledFor(logging.INFO):
             return
 
-        metric_names = self._storage.get_study_system_attrs(self._study_id).get(
-            _SYSTEM_ATTR_METRIC_NAMES
-        )
+        metric_names = self.metric_names
 
         if len(trial.values) > 1:
             trial_values: list[float] | dict[str, float]
diff --git a/optuna/visualization/_pareto_front.py b/optuna/visualization/_pareto_front.py
index 05365a5583..c7f8a0f809 100644
--- a/optuna/visualization/_pareto_front.py
+++ b/optuna/visualization/_pareto_front.py
@@ -11,7 +11,6 @@
 from optuna.exceptions import ExperimentalWarning
 from optuna.study import Study
 from optuna.study._multi_objective import _get_pareto_front_trials_by_trials
-from optuna.study.study import _SYSTEM_ATTR_METRIC_NAMES
 from optuna.trial import FrozenTrial
 from optuna.trial import TrialState
 from optuna.visualization._plotly_imports import _imports
@@ -343,9 +342,7 @@ def _infer_n_targets(
         )
 
     if target_names is None:
-        metric_names = study._storage.get_study_system_attrs(study._study_id).get(
-            _SYSTEM_ATTR_METRIC_NAMES
-        )
+        metric_names = study.metric_names
         if metric_names is None:
             target_names = [f"Objective {i}" for i in range(n_targets)]
         else: