Feature: Add server side cursors option (MIT-LCP#2333)

This option is responsible for a specific django behaviour about
querying the database, if enabled the database calls will be sectioned
and fetched in a few smaller calls, to which we need constant database
connection. We would like to change our database management
tool(pgbouncer) to transaction mode and to do that we would need to
disable that default django behaviour. The implementation only adds an
option to change it which defaults to the same behaviour as it is now.
We will change that on our side by env variables

physionet-django/physionet/settings/production.py

@@ -18,6 +18,7 @@
         'PASSWORD': config('DB_PASSWORD'),
         'HOST': config('DB_HOST'),
         'PORT': config('DB_PORT', default=''),
+        'DISABLE_SERVER_SIDE_CURSORS': config('DISABLE_SERVER_SIDE_CURSORS', default=False, cast=bool),
     }
 }
 

physionet-django/physionet/settings/settings.py

@@ -17,6 +17,7 @@
         'PASSWORD': config('DB_PASSWORD'),
         'HOST': config('DB_HOST'),
         'PORT': config('DB_PORT', default=''),
+        'DISABLE_SERVER_SIDE_CURSORS': config('DISABLE_SERVER_SIDE_CURSORS', default=False, cast=bool),
         'TEST': {
             'MIRROR': 'default'
         },

physionet-django/physionet/settings/staging.py

@@ -18,6 +18,7 @@
         'PASSWORD': config('DB_PASSWORD'),
         'HOST': config('DB_HOST'),
         'PORT': config('DB_PORT', default=''),
+        'DISABLE_SERVER_SIDE_CURSORS': config('DISABLE_SERVER_SIDE_CURSORS', default=False, cast=bool),
     }
 }