Not sure if its ideal but if you need dates in epoch millis, you could round the timestamp to the floor of the current day (say midnight) in a map function, use a built in reduce... Then use a list function to filter unique countries.
If you don't need a real timestamp value, use an integer like YYYYMMDD (i.e. 20130710 for 2013-Jul-10). Reduce = true will combine by day making at most (196 countries x number of days in range) to filter in the show function. - JK Sent from my iPad On Apr 14, 2013, at 6:38 PM, "Andrey Kuprianov" <[email protected]> wrote: > Hi guys, > > Just for the sake of a debate. Here's the question. There are transactions. > Among all other attributes there's timestamp (when transaction was made; in > seconds) and a country name (from where the transaction was made). So, for > instance, > > { > . . . . > "timestamp": 1332806400 > "country_name": "Australia", > . . . . > } > > Question is: how does one get unique / distinct country names in between > dates? For example, give me all country names in between 10-Jul-2010 and > 21-Jan-2013. > > My solution was to write a custom reduce function and set > reduce_limit=false, so that i can enumerate all countries without hitting > the overflow exception. It works great! However, such solutions are frowned > upon by everyone around. Has anyone a better idea on how to tackle this > efficiently? > > Andrey
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