Re: Win32 timezone matching - Mailing list pgsql-hackers

From Magnus Hagander
Subject Re: Win32 timezone matching
Date
Msg-id i2k9837222c1004061452ka54a675r8eeaeb2c320811ff@mail.gmail.com
Whole thread Raw
In response to Re: Win32 timezone matching  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Win32 timezone matching  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: Win32 timezone matching  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Tue, Apr 6, 2010 at 23:44, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Magnus Hagander <magnus@hagander.net> writes:
>> When diagnosing a problem for a guy in the german channel (with Stefan
>> as mediator :P), we've found a case where the timezone information in
>> the registry seem to be empty for some timezones. The current timezone
>> matching code will abort scanning when it comes across one of these,
>> thus claiming it can't match the timezone, and reverting to GMT.
>
>> We've seen some reports prevously that looked like this, but never
>> really managed to get it diagnosed. Having checked the registry on
>> this machine, it appears to simply be that "Std" and "Dlt" are missing
>> from some entries.
>
>> The attach patch changes our scan to skip to the next timezone when
>> this happens, instead of aborting. The only downtime I can see from
>> this is that in case there are a *lot* of broken timezones (like "all
>> of them"), well log a lot of warnings. But it will only happen on
>> server startup, so I think it's ok.
>
> I'm not clear on this.  Would this patch fix a real seen-in-the-field
> condition, or is it speculative?  In particular, if the loop had kept
> going in the complainant's machine, would it have found another entry
> that worked better?

Real, seen-in-the-field. It would proceed and eventually find the guys
Berlin timezone (Central European, which comes after Central Brazilian
which is the one that was missing the entries).

It does, however, turn out that the issue was fixed when he re-applied
the latest timezone update hotfix from microsoft, which appears to
rewrite that entire subkey. Not sure how well we can trust that though
- it's not like we're working off a documented key...

-- Magnus HaganderMe: http://www.hagander.net/Work: http://www.redpill-linpro.com/


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