Re: Backend protocol wanted features

On Tue, Jan 5, 2016 at 7:45 PM, Álvaro Hernández Tortosa <aht(at)8kdata(dot)com>
wrote:

> There are other parts of the protocol that require a separate connection.
> Those I don't like either, but it's not unheard of. Maybe the solution is
> different: that LD may be consumed within the same connection (if that
> would be possible).
>

Why not use the existing LISTEN/NOTIFY infrastructure for this? If there
were a reserved namespace (ex: pg_% or pg_schema_%) then the existing
protocol could be used to listen for schema changes.

There would still need to be backend support for publishing those changes
but it'd be backwards compatible in both directions; it wouldn't break
existing clients and a modern client that issued a LISTEN for those changes
could work with an older backend that doesn't support it (it just won't
receive any notifications).

Full support for something like this would require well defined message
types to indicate what changed. For an initial version it might be easier
to just have a "something changed" message without the specifics of which
relations where impacted. A client could invalidate all prepared statements
associated with the connection.

Just my 2 cents...

Regards,
-- Sehrope Sarkuni
Founder & CEO | JackDB, Inc. | https://www.jackdb.com/