finding the median of a trillion numbers
http://matpalm.com/median
see above page for walkthrough, basic instructions follow
 
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generate a list of (approx) 1000 numbers whose min is 1, max is 100 and median is 40
spread this across 4 files; numbers.0, numbers.1, numbers.2, numbers.3

bash> ./generate_test_data.rb 1 40 100 1000 > numbers.all
bash> cat numbers.all | ./spread_across_files.rb numbers 4

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run ruby version

bash> ./median.rb < numbers.all

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run erlang single process version

bash> erl -noshell -run median from_file numbers.all

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run erlang multiple process version (all processes on local machine) using full list impl

bash> erl -noshell -sname bob -run controller init worker numbers.[0-3]

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run erlang multiple process version (all processes on local machine) using list freq impl

bash> erl -noshell -run generate_binary_dicts main numbers.all numbers.dict 4
bash> erl -noshell -sname bob -run controller init worker_freq numbers.dict.[0-3]