Re: timestamp skew during 7.4 -> 8.2 upgrade

On 8/9/07, Louis-David Mitterrand
<vindex+lists-pgsql-general@apartia.org> wrote:
> Hi,
>
> After our 7.4 to 8.2 upgrade using debian tools, we realized that some
> of our timestamps with tz had shifted:
>
> For example '2007-04-01 00:00:00+02' became '2007-03-31 23:00:00+01'
> which is on a different month. Some of our applications were severely
> disturbed by that.
>
> Has anyone noticed that? Is there a way that would could have avoided
> it?

Since timestamptz is stored as a GMT time, and then an offset is
applied on retrieval, I'd guess that with 8.2 you're using up to date
timezone files, and with 7.4 they were out of date and therefore
returning the wrong time.  I.e. they had the wrong offset for a given
date.

Not sure how you could avoid it off the top of my head, besides
keeping your 7.4 db tz data up to date.