bug fix: sql lock for parallel processing

setup.py

@@ -8,7 +8,7 @@ def read(fname):
     return open(os.path.join(os.path.dirname(__file__), fname)).read() 
 args    = {
     "name":"data-transport",
-    "version":"1.5.2",
+    "version":"1.5.3",
     "author":"The Phi Technology LLC","author_email":"info@the-phi.com",
     "license":"MIT",
     "packages":["transport"]}

transport/sql.py

@@ -59,7 +59,7 @@ class SQLRW :
         #     _info['host'] = 'localhost' if 'host' not in _args else _args['host']
         #     # _info['port'] = SQLWriter.PROVIDERS[_args['provider']] if 'port' not in _args else _args['port']
         #     _info['port'] = SQLWriter.REFERENCE[_provider]['port'] if 'port' not in _args else _args['port']
-        
+        self.lock = False if 'lock' not in _args else _args['lock']
         if 'username' in _args or 'user' in _args:
             key = 'username' if 'username' in _args else 'user'
             _info['user'] = _args[key]
@@ -272,6 +272,7 @@ class SQLWriter(SQLRW,Writer):
             if _info.shape[0] == 0 :
                 
                 return
+            if self.lock :
                 SQLRW.lock.acquire()
             
             if self._engine is not None:
@@ -299,6 +300,7 @@ class SQLWriter(SQLRW,Writer):
             
             if self._engine is None :
                 self.conn.commit()   
+            if self.lock :
                 SQLRW.lock.release()         
             # cursor.close()
             pass