[PATCH v2 02/14] vinyl: introduce statement environment

[Vladimir Davydov]

On Wed, Mar 13, 2019 at 11:58:03AM +0300, Konstantin Osipov wrote:
> * Vladimir Davydov <vdavydov.dev at gmail.com> [19/03/13 11:53]:
> > Store tuple_format_vtab, max_tuple_size, and key_format there.
> > This will allow us to determine a statement type (key or tuple)
> > by checking its format against key_format.
> 
> What exactly is a key format?

It's the format we use for creating all key statements. It's kinda
pseudo format, as it imposes no restriction on the tuple and doesn't
setup offset map.

> Is there a single global key format?

Yes. It's a crux: we use to identify key statements.

> Why do you need it and why is it sufficient to have a single key
> format?

> Please explain in the comment for stmt_env->key_format.

OK, will do.