Re: Timezone database questions

>> >1) How do we set the default local timezone for our
>database? The OS
>> >knows the local timezone. How do we set our local timezone
>on Win32?
>> >On Unix? (On Unix, there is usually an /etc/localtime file that is
>> >created during install.) Perhaps we can query the current timezone
>> >specification (e.g. EDT), and do some kind of lookup. I
>know of no way
>> >to get the full specification, e.g. EST5EDT or America/New_York.
>>
>> Could we just require that it is configured through postgresql.conf?
>> IIRC there is a parameter to set it there. IMO, that would be enough.
>
>We would get too many problem reports we would get if we always
>defaulted the database timezone to GMT. We have to set the default,
>perhaps during initdb. (I just posted something else explaining why we
>should have initdb set sharedir and libdir too.)

Set the defualt timezone at initdb sounds a bit weird. Again, timezone
stuff is only used to present data, not to change it. You can even
change it during a transaction. Setting the default at inidb seems
weird. If you want to set the default, use postgresql.conf. Otherwise,
we need to pick it up somewhere else.

>> If not, we can use GetTimeZoneInformation(). It returns the standard
>> name (amongst other things) of the tz configured in the system.
>
>Yep, we will need that, and for Unix too.

Can't tell you how to do it on Unix :-(

>> Or do nothing. On unix it defaults to the value of the TZ environment
>> variables. If you set that one before you start it, you get the same
>> behaviour. In that case, I'd still say we *recommend* setting it in
>> postgresql.conf, but it will still work.
>
>Right now I think it defaults to the OS timezone if you don't
>set PGTZ.
>We can't require everyone to set PGTZ to get a reasonable default
>timezone.

Note - TZ, not PGTZ. At least it says so in the postgresql.conf that is
installed. So it's at least a standard env variable, and not a PG only
one. I don't know how often this one is actually set, though.

//Magnus

Magnus Hagander wrote:
> >> >1) How do we set the default local timezone for our
> >database? The OS
> >> >knows the local timezone. How do we set our local timezone
> >on Win32?
> >> >On Unix? (On Unix, there is usually an /etc/localtime file that is
> >> >created during install.) Perhaps we can query the current timezone
> >> >specification (e.g. EDT), and do some kind of lookup. I
> >know of no way
> >> >to get the full specification, e.g. EST5EDT or America/New_York.
> >>
> >> Could we just require that it is configured through postgresql.conf?
> >> IIRC there is a parameter to set it there. IMO, that would be enough.
> >
> >We would get too many problem reports we would get if we always
> >defaulted the database timezone to GMT. We have to set the default,
> >perhaps during initdb. (I just posted something else explaining why we
> >should have initdb set sharedir and libdir too.)
>
> Set the defualt timezone at initdb sounds a bit weird. Again, timezone
> stuff is only used to present data, not to change it. You can even
> change it during a transaction. Setting the default at inidb seems
> weird. If you want to set the default, use postgresql.conf. Otherwise,
> we need to pick it up somewhere else.

Yea, sorry, I meant to say we need to pick up the local timezone on
postmaster start.

> >> If not, we can use GetTimeZoneInformation(). It returns the standard
> >> name (amongst other things) of the tz configured in the system.
> >
> >Yep, we will need that, and for Unix too.
>
> Can't tell you how to do it on Unix :-(
>
>
> >> Or do nothing. On unix it defaults to the value of the TZ environment
> >> variables. If you set that one before you start it, you get the same
> >> behaviour. In that case, I'd still say we *recommend* setting it in
> >> postgresql.conf, but it will still work.
> >
> >Right now I think it defaults to the OS timezone if you don't
> >set PGTZ.
> >We can't require everyone to set PGTZ to get a reasonable default
> >timezone.
>
> Note - TZ, not PGTZ. At least it says so in the postgresql.conf that is
> installed. So it's at least a standard env variable, and not a PG only
> one. I don't know how often this one is actually set, though.

Yes, sorry, TZ. It is not set on my box.

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