Re: Removing pg_migrator limitations

Greg Stark wrote:
> On Sun, Dec 27, 2009 at 8:13 PM, Bruce Momjian <bruce@momjian.us> wrote:
> > Well, I think the checksums are going in the item pointers, so there
> > isn't any new storage space --- my guess is that the page version number
> > will control how the backend stores the checksum. ?Basically the backend
> > will need to read old and new page versions. ?I don't think this is
> > something pg_migrator can handle cleanly.
> 
> I thought our plan was to only read old page versions and
> automatically rewrite them to new page versions. We'll have to add the
> hooks and the page rewrite code  to do that, no?

Well, the idea of only reading the old version is so we didn't have to
carry around a lot of type-specific information in the backend, but I am
not sure if that applies to a hint bit change.

> Is that something we're comfortable adding in the final commitfest?

Uh, no idea.  It would be nice, of course.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +