Re: [HACKERS] PGUpgrade WAS: Audio interview

Jeff Davis wrote:
> Hannu Krosing wrote:
> >
> > How hard would it be to modify postgres so that it can handle multiple
> > heap page formats ?
>
> If the on-disk format is changed to add a feature (rather that for some
> performance reason), then that would mean that the feature would have to
> be available or not per disk page. Wouldn't that cause problems?

Yeah, it would be problematic and difficult to handle.  For example in
subtransactions it would be a hassle to handle the 7.4 heap page format,
maybe impossible without race conditions.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.