Re: efficient data reduction (and deduping)

Ah, yes, that makes sense. Thank you!

On Thu, Mar 1, 2012 at 11:39 AM, Claudio Freire <klaussfreire(at)gmail(dot)com>wrote:

> On Thu, Mar 1, 2012 at 4:35 PM, Alessandro Gagliardi
> <alessandro(at)path(dot)com> wrote:
> > Interesting solution. If I'm not mistaken, this does solve the problem of
> > having two entries for the same user at the exact same time (which
> violates
> > my pk constraint) but it does so by leaving both of them out (since
> there is
> > no au1.hr_timestamp > au2.hr_timestamp in that case). Is that right?
>
> Yes, but it would have to be same *exact* time (not same hour).
>
> You can use more fields to desambiguate too, ie:
>
> au1.hr_timestamp > au2.hr_timestamp or (au1.hr_timestamp ==
> au2.hr_timestamp and au1.some_other_field > au2.some_other_field)
>
> If you have a sequential id to use in desambiguation, it would be best.
>