Re: Re: xReader, double-effort (was: Temporary tables under hot standby)

On Friday, April 27, 2012 11:04:04 PM Kevin Grittner wrote:
> [replaced bad email address for Josh (which was my fault)]
>
> Aakash Goel <aakash(dot)bits(at)gmail(dot)com> wrote:
> > All, the wiki page is now up at
> >
> > http://wiki.postgresql.org/wiki/XReader.
>
> Note that the approach Aakash is taking doesn't involve changes to
> the backend code, it is strictly a standalone executable to which
> functions as a proxy to a hot standby and to which clients like
> replications systems connect. There is a possible additional
> configuration which wouldn't require a hot standby, if time permits.
> I am not clear on whether 2nd Quadrant's code takes this approach
> or builds it into the server. I think we need to know that much
> before we can get very far in discussion.
In the current, prototypal, state there is one component thats integrated into
the server (because it needs information thats only available there). That
component is layered ontop of a totally generic xlog reading/parsing library
that doesn't care at all where its running. Its also used in another cluster
to read the received (filtered) stream.
I plan to submit the XLogReader (thats what its called atm) before everything
else, so everybody can take a look as soon as possible.

I took a *very* short glance over the current wiki description of xReader and
from that it seems to me it would benefit from trying to make it
architecturally more similar to the rest of pg. I also would suggest reviewing
how the current walreceiver/sender, and their protocol, work.

Andres

--
Andres Freund http://www.2ndQuadrant.com/
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