SQLAlchemy monitors attribute modifications automatically for all

  objects it knows about and syncs them to the database.

SQLAlchemy also flushes changes to the database automatically; manually

calling ``Session().flush`` is usually only necessary when the Python

code needs the database to assign an "auto-increment" primary key ID to

a freshly created model object (before flushing, the ID attribute will

be ``None``).

Debugging

^^^^^^^^^

``DEBUG`` or ``INFO`` level, especially ``[logger_kallithea]``, but perhaps

also other loggers. It is often easier to add additional ``log`` or ``print``

statements than to use a Python debugger.

Sometimes it is simpler to disable ``errorpage.enabled`` and perhaps also

``trace_errors.enable`` to expose raw errors instead of adding extra

processing. Enabling ``debug`` can be helpful for showing and exploring

tracebacks in the browser, but is also insecure and will add extra processing.

TurboGears2 DebugBar

^^^^^^^^^^^^^^^^^^^^