[Pkg-postgresql-public] release-notes: Purging uninstalled packages

[Karl O. Pinc]

On 11/24/2014 07:31:19 AM, Karl O. Pinc wrote:
> Attached is a patch that a) simplifies the language by cutting
> out words.  b) adds a little additional explanation.

I've not tried the documented upgrade process 
(https://www.debian.org/releases/jessie/amd64/release-notes/ch-upgrading.en.html#newkernel)
but I
believe there's a serious problem here having to
do with recommending that a purge takes place
_before_ system reboot.

1st, the old kernel, although upgraded, will still
(AFICT) be running.  Trying to purge a running kernel
is ungood.  The purge of the kernel must be delayed
until after reboot.

2nd, I believe the following warning should
be included in the docs:

  WARNING

  Some packages, notably PostgreSQL (and the kernel),
  leave the bulk of their executables installed and
  running to facilitate upgrade to the newly installed
  version.  These packages must NOT be purged until
  after following the upgrade instructions found
  in /usr/share/doc/<package>/README.Debian*.
  Purging such packages before migrating to the package's
  new version can introduce substantial complications.

The phrase "(and the kernel)" could be modified to
"(and the kernel, as noted)" or something else depending
on how the kernel purge is addressed.

Note that the kernel package warns the user when he
tries to purge a running kernel.  The postgres package,
last I checked, does not warn in similar circumstances.
I'd be nice if postgres had such a check, and perhaps
if there was policy to cover any other such cases.

Regards,

Karl <kop at meme.com>
Free Software:  "You don't pay back, you pay forward."
                 -- Robert A. Heinlein