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
>
