diff --git a/platypush/plugins/db/__init__.py b/platypush/plugins/db/__init__.py
index a1d4c51a..70708bd8 100644
--- a/platypush/plugins/db/__init__.py
+++ b/platypush/plugins/db/__init__.py
@@ -25,7 +25,7 @@ class DbPlugin(Plugin):
     _db_error_wait_interval = 5.0
     _db_error_retries = 3
 
-    def __init__(self, engine=None, *args, **kwargs):
+    def __init__(self, engine=None, **kwargs):
         """
         :param engine: Default SQLAlchemy connection engine string (e.g.
             ``sqlite:///:memory:`` or ``mysql://user:pass@localhost/test``)
@@ -42,7 +42,7 @@ class DbPlugin(Plugin):
 
         super().__init__()
         self.engine_url = engine
-        self.engine = self.get_engine(engine, *args, **kwargs)
+        self.engine = self.get_engine(engine, **kwargs)
 
     def get_engine(
         self, engine: Optional[Union[str, Engine]] = None, *args, **kwargs
@@ -66,16 +66,14 @@ class DbPlugin(Plugin):
         return self.engine
 
     @staticmethod
-    def _build_condition(table, column, value):  # type: ignore
-        if isinstance(value, str):
-            value = "'{}'".format(value)
-        elif not isinstance(value, int) and not isinstance(value, float):
-            value = "'{}'".format(str(value))
+    def _build_condition(table, column, value):  # pylint: disable=unused-argument
+        if isinstance(value, str) or not isinstance(value, (int, float)):
+            value = f"'{value}'"
 
-        return eval('table.c.{}=={}'.format(column, value))
+        return eval(f'table.c.{column}=={value}')  # pylint: disable=eval-used
 
     @action
-    def execute(self, statement, engine=None, *args, **kwargs):
+    def execute(self, statement, *args, engine=None, **kwargs):
         """
         Executes a raw SQL statement.
 
@@ -98,37 +96,37 @@ class DbPlugin(Plugin):
             (see https:///docs.sqlalchemy.org/en/latest/core/engines.html)
         """
 
-        engine = self.get_engine(engine, *args, **kwargs)
+        with self.get_engine(engine, *args, **kwargs).connect() as connection:
+            connection.execute(text(statement))
 
-        with engine.connect() as connection:
-            connection.execute(statement)
-
-    def _get_table(self, table, engine=None, *args, **kwargs):
+    def _get_table(self, table: str, *args, engine=None, **kwargs):
         if not engine:
             engine = self.get_engine(engine, *args, **kwargs)
 
         db_ok = False
         n_tries = 0
         last_error = None
+        table_ = None
 
         while not db_ok and n_tries < self._db_error_retries:
             try:
                 n_tries += 1
                 metadata = MetaData()
-                table = Table(table, metadata, autoload=True, autoload_with=engine)
+                table_ = Table(table, metadata, autoload_with=engine)
                 db_ok = True
             except Exception as e:
                 last_error = e
                 wait_time = self._db_error_wait_interval * n_tries
                 self.logger.exception(e)
-                self.logger.info('Waiting {} seconds before retrying'.format(wait_time))
+                self.logger.info('Waiting %s seconds before retrying', wait_time)
                 time.sleep(wait_time)
                 engine = self.get_engine(engine, *args, **kwargs)
 
         if not db_ok and last_error:
             raise last_error
 
-        return table, engine
+        assert table_, f'No such table: {table}'
+        return table_, engine
 
     @action
     def select(
@@ -324,17 +322,16 @@ class DbPlugin(Plugin):
                     connection, table, records, key_columns
                 )
 
-            with connection.begin():
-                if insert_records:
-                    insert = table.insert().values(insert_records)
-                    ret = self._execute_try_returning(connection, insert)
-                    if ret:
-                        returned_records += ret
+            if insert_records:
+                insert = table.insert().values(insert_records)
+                ret = self._execute_try_returning(connection, insert)
+                if ret:
+                    returned_records += ret
 
-                if update_records and on_duplicate_update:
-                    ret = self._update(connection, table, update_records, key_columns)
-                    if ret:
-                        returned_records = ret + returned_records
+            if update_records and on_duplicate_update:
+                ret = self._update(connection, table, update_records, key_columns)
+                if ret:
+                    returned_records = ret + returned_records
 
         if returned_records:
             return returned_records
@@ -365,8 +362,9 @@ class DbPlugin(Plugin):
 
         query = table.select().where(
             or_(
-                and_(
-                    self._build_condition(table, k, record.get(k)) for k in key_columns
+                and_(  # type: ignore
+                    self._build_condition(table, k, record.get(k))
+                    for k in key_columns  # type: ignore
                 )
                 for record in records
             )
@@ -498,13 +496,13 @@ class DbPlugin(Plugin):
 
         engine = self.get_engine(engine, *args, **kwargs)
 
-        with engine.connect() as connection, connection.begin():
+        with engine.connect() as connection:
             for record in records:
-                table, engine = self._get_table(table, engine=engine, *args, **kwargs)
-                delete = table.delete()
+                table_, engine = self._get_table(table, engine=engine, *args, **kwargs)
+                delete = table_.delete()
 
                 for k, v in record.items():
-                    delete = delete.where(self._build_condition(table, k, v))
+                    delete = delete.where(self._build_condition(table_, k, v))
 
                 connection.execute(delete)
 
@@ -514,7 +512,7 @@ class DbPlugin(Plugin):
 
     @contextmanager
     def get_session(
-        self, engine=None, locked=False, autoflush=True, *args, **kwargs
+        self, *args, engine=None, locked=False, autoflush=True, **kwargs
     ) -> Generator[Session, None, None]:
         engine = self.get_engine(engine, *args, **kwargs)
         if locked:
@@ -523,16 +521,20 @@ class DbPlugin(Plugin):
             # Mock lock
             lock = RLock()
 
-        with lock, engine.connect() as conn, conn.begin():
-            session = scoped_session(
+        with lock, engine.connect() as conn:
+            session_maker = scoped_session(
                 sessionmaker(
                     expire_on_commit=False,
                     autoflush=autoflush,
                 )
             )
 
-            session.configure(bind=conn)
-            yield session()
+            session_maker.configure(bind=conn)
+            session = session_maker()
+            yield session
+
+            session.flush()
+            session.commit()
 
 
 # vim:sw=4:ts=4:et:
diff --git a/platypush/plugins/entities/__init__.py b/platypush/plugins/entities/__init__.py
index 443cf51a..74caf3cd 100644
--- a/platypush/plugins/entities/__init__.py
+++ b/platypush/plugins/entities/__init__.py
@@ -3,7 +3,7 @@ from threading import Thread
 from time import time
 from typing import Optional, Any, Collection, Mapping
 
-from sqlalchemy import or_
+from sqlalchemy import or_, text
 from sqlalchemy.orm import make_transient, Session
 
 from platypush.config import Config
@@ -198,7 +198,7 @@ class EntitiesPlugin(Plugin):
             if str(session.connection().engine.url).startswith('sqlite://'):
                 # SQLite requires foreign_keys to be explicitly enabled
                 # in order to proper manage cascade deletions
-                session.execute('PRAGMA foreign_keys = ON')
+                session.execute(text('PRAGMA foreign_keys = ON'))
 
             entities: Collection[Entity] = (
                 session.query(Entity).filter(Entity.id.in_(entities)).all()
diff --git a/platypush/plugins/variable/__init__.py b/platypush/plugins/variable/__init__.py
index 0346ba88..9556b07f 100644
--- a/platypush/plugins/variable/__init__.py
+++ b/platypush/plugins/variable/__init__.py
@@ -1,6 +1,21 @@
-from platypush.config import Config
+from sqlalchemy import Column, String
+
+from platypush.common.db import declarative_base
 from platypush.context import get_plugin
 from platypush.plugins import Plugin, action
+from platypush.plugins.db import DbPlugin
+
+Base = declarative_base()
+
+
+# pylint: disable=too-few-public-methods
+class Variable(Base):
+    """Models the variable table"""
+
+    __tablename__ = 'variable'
+
+    name = Column(String, primary_key=True, nullable=False)
+    value = Column(String)
 
 
 class VariablePlugin(Plugin):
@@ -11,8 +26,6 @@ class VariablePlugin(Plugin):
     will be stored either persisted on a local database or on the local Redis instance.
     """
 
-    _variable_table_name = 'variable'
-
     def __init__(self, **kwargs):
         """
         The plugin will create a table named ``variable`` on the database
@@ -21,24 +34,14 @@ class VariablePlugin(Plugin):
         """
 
         super().__init__(**kwargs)
-        self.db_plugin = get_plugin('db')
-        self.redis_plugin = get_plugin('redis')
+        db_plugin = get_plugin('db')
+        redis_plugin = get_plugin('redis')
+        assert db_plugin, 'Database plugin not configured'
+        assert redis_plugin, 'Redis plugin not configured'
 
-        db = Config.get('db')
-        self.db_config = {
-            'engine': db.get('engine'),
-            'args': db.get('args', []),
-            'kwargs': db.get('kwargs', {})
-        }
-
-        self._create_tables()
-        # self._variables = {}
-
-    def _create_tables(self):
-        self.db_plugin.execute("""CREATE TABLE IF NOT EXISTS {}(
-            name varchar(255) not null primary key,
-            value text
-        )""".format(self._variable_table_name))
+        self.redis_plugin = redis_plugin
+        self.db_plugin: DbPlugin = db_plugin
+        self.db_plugin.create_all(self.db_plugin.get_engine(), Base)
 
     @action
     def get(self, name, default_value=None):
@@ -53,13 +56,10 @@ class VariablePlugin(Plugin):
         :returns: A map in the format ``{"<name>":"<value>"}``
         """
 
-        rows = self.db_plugin.select(table=self._variable_table_name,
-                                     filter={'name': name},
-                                     engine=self.db_config['engine'],
-                                     *self.db_config['args'],
-                                     **self.db_config['kwargs']).output
+        with self.db_plugin.get_session() as session:
+            var = session.query(Variable).filter_by(name=name).first()
 
-        return {name: rows[0]['value'] if rows else default_value}
+        return {name: (var.value if var is not None else default_value)}
 
     @action
     def set(self, **kwargs):
@@ -69,15 +69,24 @@ class VariablePlugin(Plugin):
         :param kwargs: Key-value list of variables to set (e.g. ``foo='bar', answer=42``)
         """
 
-        records = [{'name': k, 'value': v}
-                   for (k, v) in kwargs.items()]
+        with self.db_plugin.get_session() as session:
+            existing_vars = {
+                var.name: var
+                for var in session.query(Variable)
+                .filter(Variable.name.in_(kwargs.keys()))
+                .all()
+            }
 
-        self.db_plugin.insert(table=self._variable_table_name,
-                              records=records, key_columns=['name'],
-                              engine=self.db_config['engine'],
-                              on_duplicate_update=True,
-                              *self.db_config['args'],
-                              **self.db_config['kwargs'])
+            new_vars = {
+                name: Variable(name=name, value=value)
+                for name, value in kwargs.items()
+                if name not in existing_vars
+            }
+
+            for name, var in existing_vars.items():
+                var.value = kwargs[name]  # type: ignore
+
+            session.add_all([*existing_vars.values(), *new_vars.values()])
 
         return kwargs
 
@@ -90,12 +99,8 @@ class VariablePlugin(Plugin):
         :type name: str
         """
 
-        records = [{'name': name}]
-
-        self.db_plugin.delete(table=self._variable_table_name,
-                              records=records, engine=self.db_config['engine'],
-                              *self.db_config['args'],
-                              **self.db_config['kwargs'])
+        with self.db_plugin.get_session() as session:
+            session.query(Variable).filter_by(name=name).delete()
 
         return True
 
@@ -150,4 +155,5 @@ class VariablePlugin(Plugin):
 
         return self.redis_plugin.expire(name, expire)
 
+
 # vim:sw=4:ts=4:et:
diff --git a/platypush/user/__init__.py b/platypush/user/__init__.py
index 7d268b59..432774a4 100644
--- a/platypush/user/__init__.py
+++ b/platypush/user/__init__.py
@@ -3,11 +3,11 @@ import datetime
 import hashlib
 import json
 import random
-import rsa
 import time
 from typing import Optional, Dict
 
 import bcrypt
+import rsa
 
 from sqlalchemy import Column, Integer, String, DateTime, ForeignKey
 from sqlalchemy.orm import make_transient
@@ -73,7 +73,7 @@ class UserManager:
                 username=username,
                 password=self._encrypt_password(password),
                 created_at=datetime.datetime.utcnow(),
-                **kwargs
+                **kwargs,
             )
 
             session.add(record)
@@ -238,9 +238,7 @@ class UserManager:
             indent=None,
         )
 
-        return base64.b64encode(
-            rsa.encrypt(payload.encode('ascii'), pub_key)
-        ).decode()
+        return base64.b64encode(rsa.encrypt(payload.encode('ascii'), pub_key)).decode()
 
     def validate_jwt_token(self, token: str) -> Dict[str, str]:
         """
@@ -263,21 +261,19 @@ class UserManager:
 
         try:
             payload = json.loads(
-                rsa.decrypt(
-                    base64.b64decode(token.encode('ascii')),
-                    priv_key
-                ).decode('ascii')
+                rsa.decrypt(base64.b64decode(token.encode('ascii')), priv_key).decode(
+                    'ascii'
+                )
             )
         except (TypeError, ValueError) as e:
-            raise InvalidJWTTokenException(f'Could not decode JWT token: {e}')
+            raise InvalidJWTTokenException(f'Could not decode JWT token: {e}') from e
 
         expires_at = payload.get('expires_at')
         if expires_at and time.time() > expires_at:
             raise InvalidJWTTokenException('Expired JWT token')
 
         user = self.authenticate_user(
-            payload.get('username', ''),
-            payload.get('password', '')
+            payload.get('username', ''), payload.get('password', '')
         )
 
         if not user:
diff --git a/setup.py b/setup.py
index eb77d9ec..48e64f1b 100755
--- a/setup.py
+++ b/setup.py
@@ -57,7 +57,7 @@ setup(
         'redis',
         'requests',
         'croniter',
-        'sqlalchemy<2.0.0',
+        'sqlalchemy',
         'websockets',
         'websocket-client',
         'wheel',