Maybe look at the pig source to see how it does it?
Russell Jurney http://datasyndrome.com
On Feb 1, 2013, at 11:37 PM, praveenesh kumar praveen...@gmail.com wrote:
Thanks for that Russell. Unfortunately I can't use Pig. Need to write
my own MR job. I was wondering how its usually done in the
My actual problem is to rank all values and then run logic 1 to top n%
values and logic 2 to rest values.
1st - Ranking ? (need major suggestions here)
2nd - Find top n% out of them.
Then rest is covered.
Regards
Praveenesh
On Sat, Feb 2, 2013 at 1:42 PM, Lake Chang lakech...@gmail.com wrote:
My suggestion is to use secondary sort with a single reducer. That easy you
can easily extract the top N. If you want to get the top N% you'll need an
additional phase to determine how many records this N% really is.
--
Met vriendelijke groet,
Niels Basjes
(Verstuurd vanaf mobiel )
Op 2 feb.
Hi,
Can you tell more about:
* How big is N
* How big is the input dataset
* How many mappers you have
* Do input splits correlate with the sorting criterion for top N?
Depending on the answers, very different strategies will be optimal.
On Fri, Feb 1, 2013 at 9:05 PM, praveenesh kumar
Actually what I am trying to find to top n% of the whole data.
This n could be very large if my data is large.
Assuming I have uniform rows of equal size and if the total data size
is 10 GB, using the above mentioned approach, if I have to take top
10% of the whole data set, I need 10% of 10GB
Pig. Datafu. 7 lines of code.
https://gist.github.com/4696443
https://github.com/linkedin/datafu
On Fri, Feb 1, 2013 at 11:17 PM, praveenesh kumar praveen...@gmail.comwrote:
Actually what I am trying to find to top n% of the whole data.
This n could be very large if my data is large.
Thanks for that Russell. Unfortunately I can't use Pig. Need to write
my own MR job. I was wondering how its usually done in the best way
possible.
Regards
Praveenesh
On Sat, Feb 2, 2013 at 1:00 PM, Russell Jurney russell.jur...@gmail.com wrote:
Pig. Datafu. 7 lines of code.
