Re: WIP checksums patch - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: WIP checksums patch
Date
Msg-id 20121001163524.GC30089@momjian.us
Whole thread Raw
In response to Re: WIP checksums patch  (Jeff Davis <pgsql@j-davis.com>)
Responses Re: WIP checksums patch  (Jeff Davis <pgsql@j-davis.com>)
List pgsql-hackers
On Mon, Oct  1, 2012 at 09:25:43AM -0700, Jeff Davis wrote:
> On Mon, 2012-10-01 at 10:43 -0400, Bruce Momjian wrote:
> > >   The default is <literal>off</> for backwards compatibility and
> > >   to allow upgrade. The recommended setting is <literal>on</> though
> > >   this should not be enabled until upgrade is successfully complete
> > >   with full set of new backups.
> > > 
> > > I don't understand what that means -- if they have the page_checksums
> > > GUC available, then surely upgrade is complete, right? And what is the
> > > backwards-compatibility issue?
> 
> > I think this need to clearly state "pg_upgrade", not a dump/restore
> > upgrade, which would be fine.  It would be interesting to have
> > pg_upgrade change this setting, or tell the user to change it.  I am not
> > sure enough people are using pg_upgrade to change a default value.
> 
> I still don't understand why pg_upgrade and page_checksums don't mix.

The heap/index files are copied unmodified from the old cluster, so
there are no checksums on the pages.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +



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