Thanks, Ning! Finding the date which is 30 days before/later was easy enough
but my problem is beyond that. I need to find unique users based on these
last 30 days for a range of days. Does that make sense?
On Fri, Oct 15, 2010 at 12:10 AM, Ning Zhang <nzh...@facebook.com> wrote:
> There are some UDFs that convert a string to epoch time and back to a
> string. e.g.,
>
> select from_unixtime(unix_timestamp('2010-10-10', 'yyyy-MM-dd') +
> 60*60*24*30, 'yyyy-MM-dd') from src limit 1;
>
> will given you the date which is 30 days later than 2010-10-10.
>
> On Oct 14, 2010, at 11:36 PM, Vijay wrote:
>
> > Hi, I need help with this scenario. We have a table of events which has
> columns date, event (not important for this discussion), and user_id. It is
> obviously easy to find number of unique users for each day. I also need to
> find number of unique users in the last 30 days for each day. This is also
> quite simple to do for one day. However, I cannot figure out how to do this
> for a range of days. Something like this is pretty straightforward in most
> RDBMS but with HiveQL has I'm finding this hard. I might be missing
> something simple though. Any help is appreciated. Ideally the query should
> also be as optimized as possible as this table could be huge.
> >
> > Thanks,
> > Vijay
> >
>
>
