Re: [COMMITTERS] pgsql: Add configure option --with-system-tzdata to use operating system

"Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

> In the first place, it is considered bad form for a package to install
> an absolute symlink to /usr/share/zoneinfo:
>
> "symlinks _should_ be relative. Even if all they have in common is /."
> - Jeremy Katz
> https://www.redhat.com/archives/fedora-maintainers/2007-August/msg00096.html
>
> Followup arguments in that thread mentioned chroots and NFS mounts as
> environments where absolute symlinks are likely to lead to the wrong
> place.

Fwiw Debian also faced this issue and came to a different conclusion. IIRC the
policy is that it's explicitly supported for a sysadmin to replace any
directory in the top level directory with a symlink. So for example /home ->
/export/home.

Therefore any package which includes a symlink which traverses between top
level directories *must* be absolute. And any symlink which does not span two
top level directories *must* be relative. So /usr/foo/bar which links to
/var/foo/bar must be absolute. But /usr/foo/bar which links to /usr/qux/bar
must be a relative link ../qux/bar.

> In short, then, the patch actually being used (as of today) in Fedora
> and ultimately RHEL is as below, and I don't see any prospect of
> substituting the mechanism Peter has created.

Why would --with-zoneinfo want to use a symlink though? Shouldn't it just
compile the binary to use the path specified directly? Symlinks are fine for a
sysadmin or a packager but if it's going to be supported by Postgres code
directly why not do it directly?

--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com