Subject Re: [Firebird-Architect] Re: Vulcan services engine info
Author Dmitry Yemanov
"Dimitry Sibiryakov" <aafemt@...> wrote:
>
> Right. SPB parsing belongs to the place where services are
> implemented. Because we are talking about implementing part of
> services (which are too global for single provider) in Y-valve, it
> must parse SPB if has to.

Y-valve would be required to always parse SPB as otherwise it cannot know
what it should to - forward the request to the engine or handle it itself.

> >I don't like it. Why functions of the utility become something that
> >the engine should handle?
>
> Because utility are ODS-bound. And so do engines.

Particularly true. fb_lock_print is not ODS bound, neither is gfix
-shut/sweep/etc.

> Then answer my question from previous letter: what version of
> backup file must be produced on the server where more than one engine
> provider handle databases with different ODS?

When GBAK performs a backup, its attachment will go through the Y-valve.
Which engine will open the database being backed up depends on ODS. But GBAK
will complete successfully anyway, producing a most recent backup version.
If you think that we should be able to produce different backup versions
within a single server installation, then what should happen with standalone
GBAK utility? Do you suggest to ship multiple GBAKs too?


Dmitry