Re: pgsql: doc: mention dependency on collation libraries

On Sat, Jul  2, 2016 at 01:22:48PM -0400, Bruce Momjian wrote:
> On Sat, Jul  2, 2016 at 06:02:12PM +0200, Christoph Berg wrote:
> > Re: Bruce Momjian 2016-07-02 <20160702155517.GD18610@momjian.us>
> > > > Shouldn't this mention that OS upgrades are a possible problem as
> > > > well? We've seen the de_DE.UTF-8 ordering break in RHEL 5->6, and
> > > > again in 6->7. (5 and 7 are compatible.) The problematic strings were
> > > > "999" and "9-9-9".
> > >
> > > Yes, we can do that.  Do you have suggested wording?  I was not sure how
> > > to tell people anything related to collation versions.
> >
> > How about simply this: ?
> >
> >    Non<literal>C</> and and non-<literal>POSIX</> locales rely on the
> >    operating system's collation library for character set ordering.
> >    This controls the ordering of keys stored in indexes.  For this
> > eason,
> >    a cluster cannot switch to an incompatible collation library
> > ersion,
> >    either through
> >
> > +  operating system upgrade,
> >
> >    snapshot restore, binary streaming replication, or
> >    <application>pg_upgrade</> run.
>
> OK, good point.  I was more focused on cluster moves than an OS change.
> How is the attached patch?

With the mention of different operating systems, there is no need to
mention pg_upgrade anymore as it is already covered.  Updated patch
attached.

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

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