diff --git a/dataset/persistence/database.py b/dataset/persistence/database.py
index 5f7cdc5..a0a9f56 100644
--- a/dataset/persistence/database.py
+++ b/dataset/persistence/database.py
@@ -25,7 +25,7 @@ log = logging.getLogger(__name__)
 class Database(object):
     def __init__(self, url, schema=None, reflect_metadata=True,
                  engine_kwargs=None, reflect_views=True,
-                 row_type=row_type):
+                 ensure_schema=True, row_type=row_type):
         if engine_kwargs is None:
             engine_kwargs = {}
 
@@ -45,6 +45,7 @@ class Database(object):
         self.engine = create_engine(url, **engine_kwargs)
         self.url = url
         self.row_type = row_type
+        self.ensure_schema = ensure_schema
         self._tables = {}
         self.metadata = MetaData(schema=schema)
         self.metadata.bind = self.engine
diff --git a/dataset/persistence/table.py b/dataset/persistence/table.py
index 4c64fe3..0a9fb32 100644
--- a/dataset/persistence/table.py
+++ b/dataset/persistence/table.py
@@ -11,7 +11,6 @@ from dataset.util import DatasetException
 
 
 log = logging.getLogger(__name__)
-ensure_session = True
 
 
 class Table(object):
@@ -53,7 +52,7 @@ class Table(object):
         if self._is_dropped:
             raise DatasetException('the table has been dropped. this object should not be used again.')
 
-    def insert(self, row, ensure=ensure_session, types={}):
+    def insert(self, row, ensure=None, types={}):
         """
         Add a row (type: dict) by inserting it into the table.
         If ``ensure`` is set, any of the keys of the row are not
@@ -72,13 +71,14 @@ class Table(object):
         Returns the inserted row's primary key.
         """
         self._check_dropped()
+        ensure = self.database.ensure_schema if ensure is None else ensure
         if ensure:
             self._ensure_columns(row, types=types)
         res = self.database.executable.execute(self.table.insert(row))
         if len(res.inserted_primary_key) > 0:
             return res.inserted_primary_key[0]
 
-    def insert_many(self, rows, chunk_size=1000, ensure=ensure_session, types={}):
+    def insert_many(self, rows, chunk_size=1000, ensure=None, types={}):
         """
         Add many rows at a time, which is significantly faster than adding
         them one by one. Per default the rows are processed in chunks of
@@ -91,6 +91,8 @@ class Table(object):
             rows = [dict(name='Dolly')] * 10000
             table.insert_many(rows)
         """
+        ensure = self.database.ensure_schema if ensure is None else ensure
+
         def _process_chunk(chunk):
             if ensure:
                 for row in chunk:
@@ -108,7 +110,7 @@ class Table(object):
         if chunk:
             _process_chunk(chunk)
 
-    def update(self, row, keys, ensure=ensure_session, types={}):
+    def update(self, row, keys, ensure=None, types={}):
         """
         Update a row in the table. The update is managed via
         the set of column names stated in ``keys``: they will be
@@ -132,6 +134,7 @@ class Table(object):
             return False
         clause = [(u, row.get(u)) for u in keys]
 
+        ensure = self.database.ensure_schema if ensure is None else ensure
         if ensure:
             self._ensure_columns(row, types=types)
 
@@ -149,7 +152,7 @@ class Table(object):
         except KeyError:
             return 0
 
-    def upsert(self, row, keys, ensure=ensure_session, types={}):
+    def upsert(self, row, keys, ensure=None, types={}):
         """
         An UPSERT is a smart combination of insert and update. If rows with matching ``keys`` exist
         they will be updated, otherwise a new row is inserted in the table.
@@ -162,6 +165,8 @@ class Table(object):
         if not isinstance(keys, (list, tuple)):
             keys = [keys]
         self._check_dropped()
+
+        ensure = self.database.ensure_schema if ensure is None else ensure
         if ensure:
             self.create_index(keys)
 
@@ -220,7 +225,8 @@ class Table(object):
                                                           _type, self.table.name))
             self.create_column(column, _type)
 
-    def _args_to_clause(self, args, ensure=ensure_session, clauses=()):
+    def _args_to_clause(self, args, ensure=None, clauses=()):
+        ensure = self.database.ensure_schema if ensure is None else ensure
         if ensure:
             self._ensure_columns(args)
         clauses = list(clauses)