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On 16/12/12 16:52, Terence Ferraro wrote:
Sorry about the double post, I thought the list disallowed attachments
so I sent it again with a pastebin link instead of an attachment.
This change does not affect the storage at all. If it did, pre-9.1
things would have been a mess. Rather, this allows the system to
determine the timezone for localized use at runtime.
Post 9.1, the system determines this via initdb data directory
initialization and automatically sets it within postgresql.conf.
In other words, the default now is *not* GMT but rather the system
detected timezone at initdb runtime. Removing that statically set
configuration option, in this case, *then* assumes GMT.
In other words, it may be 2 AM NZST, but would you really want to walk
around and have all of your clocks read 1 PM (GMT)? :)
T.J.
On Sat, Dec 15, 2012 at 10:35 PM, Gavin Flower
<gavinflo...@archidevsys.co.nz <mailto:gavinflo...@archidevsys.co.nz>>
wrote:
On 16/12/12 16:07, Terence Ferraro wrote:
We recently began upgrading our clients' servers from 9.0 -> 9.2.
After a few deployments and a little digging we noticed that 9.0
-> 9.1 broke the use of no timezone set within postgresql.conf.
That is, not setting the option was now defaulting to GMT instead
of the system timezone. Unfortunately, this put quite a damper on
our "one configuration file to rule them all" setup across
servers located throughout various time zones.
I obtained the commit ca4af308c32d03db5fbacb54d6e583ceb904f268
from the git repository and have reversed it against 9.2. Though
it didn't apply as smoothly as initially hoped; applying a few of
the failed hunks manually allowed me to successfully compile
9.2.1 with these changes reversed.
After some (light) testing, the previous functionality of the
system choosing the timezone at runtime seems to be functional again.
I found this functionality invaluable and figured I'd get the
patch (http://pastebin.com/5AyaX2RF) posted in case anyone else
ever needs this functionality back. It works against 9.2.1; no
guarantees on future releases of course and YMMV.
T.J.
I simply do not understand why you would _NOT_ want to store
date/times as GMT!
Storing as GMT, allows the times to be easily converted into
whatever time zone you are in, also allows for times to be
correctly ordered irrespective of time zone.
If I make a phone call from Auckland to New York at 2am NZST on
Friday, thenmy colleague is talking to me at the same time - even
though it is still Thursday for them!
Cheers,
Gavin
My machine time is stored in GMT, but displayed in local time. If I
store time as the local time zone, then I could end up with a file
created after I had amended it, or having a negative uptime! Similarly,
I want my date/times to be stored in GMT, but displayed in local time.
This is similar to storing money as an integer value of cents then
formatting it for output with 2 decimal place. Storing money as a
double, is a common programming error - though, sometimes storing money
as a double is actually valid.
The key point is the storage type used should be one most appropriate
for processing, and need not be what is displayed. In a database,
someone's name will normally be stored in 2 or fields, but printed out
as if it had been stored as a single string.
Cheers,
Gavin
