Re: Daylight Saving Time question PostgreSQL 8.1.4

Tom Lane wrote:
> Josh Berkus <josh@agliodbs.com> writes:
>> Zdenec,
>>> I have following idea:
>>> 1) add guc varibale which enable usage of OS time zone files
>>> 2) add extra parameters into ./configure script which enable OS TZ
>>> support in the code and get path to OS TZ files.
> 
>> If we're adding it as a configure-time variable, there's no reason to have 
>> a GUC.
> 
> I see zero reason to have either.  It would only make sense to do this
> in the context of a platform-specific distribution such as an RPM, and
> in that context the simplest solution is to let the RPM specfile make
> the substitution (ie, after "make install" and before packaging,
> rm -rf PG's timezone tree and insert a symlink).  Then it's on the RPM
> packager's head whether it's the right thing to do or not.   A configure
> switch strikes me as mostly a foot-gun, because the average user of
> Postgres won't have any way to know whether the files are compatible.

I don't think to make a symlink is good solution. It generates a lot of 
future problem with package update or patching. Configure switch is much 
comfortable for packagers/patch makers.  In case when average user want 
to compile own postgres we can offer regression test focused on TZ 
validation. (By the way average user is surprise, that postgres has own 
zone files)

I also think, usage system's timezone files should be by default and 
configure script determines zonefiles location based on OS. Another 
location could be set by switch.  If for some platform will be necessary 
use own copy, special switch (e.g. --enable-internal-tzfiles) setup 
postgres for process own timezone copy.

    Zdenek

PS: For information there are TZ locations on several OS:

/usr/share/lib/zoneinfo Solaris
/usr/share/zoneinfo    Redhat
/opt/dce/lib/zoneinfo   HP-UX (no TZif magic word)
/etc/zoneinfo/          Tru64 (no TZif magic word)
/usr/share/zoneinfo/    MacOS
<registers>        MS Windows