diff --git a/src/db_config.py b/src/db_config.py
index 29064ca..75ee739 100644
--- a/src/db_config.py
+++ b/src/db_config.py
@@ -12,12 +12,16 @@
 
 SQLALCHEMY_DATABASE_URL = os.environ["SQLALCHEMY_DATABASE_URL"]
 
-engine = create_async_engine(SQLALCHEMY_DATABASE_URL)
+engine = create_async_engine(
+    SQLALCHEMY_DATABASE_URL,
+    pool_size=15,
+    max_overflow=15,
+    pool_timeout=30,
+    )
 sync_engine = create_engine(SQLALCHEMY_DATABASE_URL)
 
 async_session_maker = async_sessionmaker(engine, expire_on_commit=False)
 
-
 # database models (SQLAlchemy)
 class Base(DeclarativeBase):  # pylint: disable=too-few-public-methods
     """Classe base para modelos SQL Alchemy.
@@ -83,10 +87,21 @@ class DbContextManager:
     """Context manager para manipulação de sessões do banco de dados.
     """
     def __init__(self):
-        self.db = async_session_maker()
+        self.async_session_maker = async_session_maker
+        self.db = None
 
     async def __aenter__(self):
+        self.db = self.async_session_maker()
         return self.db
 
     async def __aexit__(self, exc_type, exc_value, traceback):
-        await self.db.close()
+        try:
+            if exc_type is None:
+                # 2. If NO exception occurred, commit the transaction.
+                await self.db.commit()
+            else:
+                # 3. If an exception DID occur, roll back the transaction.
+                await self.db.rollback()
+        finally:
+            # 4. ALWAYS close the session.
+            await self.db.close()