diff --git a/.github/workflows/tests-with-minimum-versions.yml b/.github/workflows/tests-with-minimum-versions.yml
index c692acf4d6..f40ec0ed14 100644
--- a/.github/workflows/tests-with-minimum-versions.yml
+++ b/.github/workflows/tests-with-minimum-versions.yml
@@ -70,7 +70,7 @@ jobs:
       run: |
         # Install dependencies with minimum versions.
         pip uninstall -y alembic cmaes packaging sqlalchemy plotly scikit-learn pillow
-        pip install alembic==1.5.0 cmaes==0.10.0 packaging==20.0 sqlalchemy==1.3.0 tqdm==4.27.0 colorlog==0.3 PyYAML==5.1 'pillow<10.4.0'
+        pip install alembic==1.5.0 cmaes==0.10.0 packaging==20.0 sqlalchemy==1.4.2 tqdm==4.27.0 colorlog==0.3 PyYAML==5.1 'pillow<10.4.0'
         pip uninstall -y matplotlib pandas scipy
         # Python v3.6 was dropped at NumPy v1.20.3.
         if [ "${{ matrix.python-version }}" = "3.7" ]; then
diff --git a/optuna/storages/_rdb/storage.py b/optuna/storages/_rdb/storage.py
index 6558fb52cf..27dd840ef5 100644
--- a/optuna/storages/_rdb/storage.py
+++ b/optuna/storages/_rdb/storage.py
@@ -9,6 +9,7 @@
 import logging
 import os
 import random
+import sqlite3
 import time
 from typing import Any
 from typing import Callable
@@ -43,6 +44,8 @@
     import alembic.migration as alembic_migration
     import alembic.script as alembic_script
     import sqlalchemy
+    import sqlalchemy.dialects.mysql as sqlalchemy_dialects_mysql
+    import sqlalchemy.dialects.sqlite as sqlalchemy_dialects_sqlite
     import sqlalchemy.exc as sqlalchemy_exc
     import sqlalchemy.orm as sqlalchemy_orm
     import sqlalchemy.sql.functions as sqlalchemy_sql_functions
@@ -55,6 +58,8 @@
     alembic_script = _LazyImport("alembic.script")
 
     sqlalchemy = _LazyImport("sqlalchemy")
+    sqlalchemy_dialects_mysql = _LazyImport("sqlalchemy.dialects.mysql")
+    sqlalchemy_dialects_sqlite = _LazyImport("sqlalchemy.dialects.sqlite")
     sqlalchemy_exc = _LazyImport("sqlalchemy.exc")
     sqlalchemy_orm = _LazyImport("sqlalchemy.orm")
     sqlalchemy_sql_functions = _LazyImport("sqlalchemy.sql.functions")
@@ -720,14 +725,36 @@ def _set_trial_user_attr_without_commit(
         trial = models.TrialModel.find_or_raise_by_id(trial_id, session)
         self.check_trial_is_updatable(trial_id, trial.state)
 
-        attribute = models.TrialUserAttributeModel.find_by_trial_and_key(trial, key, session)
-        if attribute is None:
-            attribute = models.TrialUserAttributeModel(
-                trial_id=trial_id, key=key, value_json=json.dumps(value)
+        if self.engine.name == "mysql":
+            mysql_insert_stmt = sqlalchemy_dialects_mysql.insert(
+                models.TrialUserAttributeModel
+            ).values(trial_id=trial_id, key=key, value_json=json.dumps(value))
+            mysql_upsert_stmt = mysql_insert_stmt.on_duplicate_key_update(
+                value_json=mysql_insert_stmt.inserted.value_json
             )
-            session.add(attribute)
+            session.execute(mysql_upsert_stmt)
+        elif self.engine.name == "sqlite" and sqlite3.sqlite_version_info >= (3, 24, 0):
+            sqlite_insert_stmt = sqlalchemy_dialects_sqlite.insert(
+                models.TrialUserAttributeModel
+            ).values(trial_id=trial_id, key=key, value_json=json.dumps(value))
+            sqlite_upsert_stmt = sqlite_insert_stmt.on_conflict_do_update(
+                index_elements=[
+                    models.TrialUserAttributeModel.trial_id,
+                    models.TrialUserAttributeModel.key,
+                ],
+                set_=dict(value_json=sqlite_insert_stmt.excluded.value_json),
+            )
+            session.execute(sqlite_upsert_stmt)
         else:
-            attribute.value_json = json.dumps(value)
+            # TODO(porink0424): Add support for other databases, e.g., PostgreSQL.
+            attribute = models.TrialUserAttributeModel.find_by_trial_and_key(trial, key, session)
+            if attribute is None:
+                attribute = models.TrialUserAttributeModel(
+                    trial_id=trial_id, key=key, value_json=json.dumps(value)
+                )
+                session.add(attribute)
+            else:
+                attribute.value_json = json.dumps(value)
 
     def set_trial_system_attr(self, trial_id: int, key: str, value: JSONSerializable) -> None:
         with _create_scoped_session(self.scoped_session, True) as session:
diff --git a/pyproject.toml b/pyproject.toml
index dd1a17777c..4f7d027323 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,7 +35,7 @@ dependencies = [
   "colorlog",
   "numpy",
   "packaging>=20.0",
-  "sqlalchemy>=1.3.0",
+  "sqlalchemy>=1.4.2",
   "tqdm",
   "PyYAML",  # Only used in `optuna/cli.py`.
 ]