Re: 2.7.2 still problem with readonly/autocommit, was: Changing set_session implementation

On Fri, Aug 11, 2017 at 12:34:35PM +0100, Daniele Varrazzo wrote:

> > After this I would assume the connection to be in readwrite
> > mode (per your explanation, psycopg2 would (also) emit a "set
> > default_trans...off" when the last readonly=False is given.
> >
> > However, it does NOT, as the PostgreSQL log snippet shows.
>
> Ok, I see your point, and yes, I think it is a bug.

Thank you very much and I am sorry for being so stubborn ! :-)

> In [9]: cnn.autocommit = False
> [23759] conn_set_session: autocommit 0, isolevel 5, readonly 2, deferrable 2
>
> In [10]: cnn.readonly = True
> [23759] conn_set_session: autocommit 0, isolevel 5, readonly 1, deferrable 2
>
> In [11]: cnn.autocommit = True
> [23759] conn_set_session: autocommit 1, isolevel 5, readonly 1, deferrable 2
>
> In [12]: cnn.readonly = True
> [23759] conn_set_session: autocommit 1, isolevel 5, readonly 1, deferrable 2
>
> The operation in [12] would be idempotent: the code checks that the
> new value is the same of the previous one and bails out early.

That was my suspicion.

> But
> checking the internal state for idempotence when in autocommit is
> wrong: the only state that matters is what's in the server session.

Aha, I understand !

> I'll take a look at the logic of the state switching.

Thanks !

Karsten
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