First attempt, loop through partitions using rbhive

compress_keywords.rb

require 'rubygems'
require 'date'
require 'rbhive'

countrys = %w[at au br de dk es fr in it jp mx nl no pl pt ru se uk us za]
dates = (Date.parse('2011-01-01')..Date.parse('2011-04-30'))

RBHive.connect('hiveserver') do |con|
  dates.each do |date|
    countrys.each do |country|
      query = "insert overwrite table keywords partition (dated='#{date}', country = '#{country}')
              select account,campaign,ad_group,keyword_id,keyword,match_type,status,
              first_page_bid,quality_score,distribution,max_cpc,destination_url,ad_group_status,
              campaign_status,currency_code,impressions,clicks,ctr,cpc,
              cost,avg_position,account_id,campaign_id,adgroup_id 
              from keywords where dated='#{date}' and country='#{country}'"
      begin
        con.set('mapred.output.compression.codec','org.apache.hadoop.io.compress.GzipCodec')
        con.set('hive.exec.compress.output','true')
        con.set('mapred.output.compress','true')
        con.set('mapred.compress.map.output','true')
        con.set('hive.merge.mapredfiles','true')
        con.set('hive.merge.mapfiles','true')
        con.execute(query)
      rescue => e
        puts "#########################"
        puts e.message
        puts "#########################"
      end
    end
  end 
end