How to randomly assign rows to be written out to csv files

[mobmsc2]

Assume I have 4 inputs (input 1, 2,3 and 4) I need to create csv files which contain randomly selected rows from each input so that each row/record is only in 1 csv file and all rows/records are used. 

My initial thought is to find the number of rows in each input and select the smallest value (call it X). Using that I would assign a random number to each row in each input between 1 and X and then aggregate the rows by the random number. 

Anyone have any other ideas ?

I found this code for random numbers in this forum post which I hope could be reused to find the next int between 1 and X

java.util.Random (package)
// for generating random number for the range b\w 0000 to 9999
int randomInt = randomGenerator.nextInt(9999)

[Jesperrekuh]

Add a (big) random value to each row, sort ascending and say you want max 100 records, simply limit on a row counter max value... I dont quite get the aggregate part?

If you get data from a database, example mysql, there is a: order by rand() limit 250

[mobmsc2]

If a big random number was added to each of the 4 inputs and then the inputs merged before sorting wouldn't there be a possibility that 100 rows you write might not contain rows from each of the inputs?

Can you explain more about 

row counter

you mention? is it a component or a setting or code?

[Jesperrekuh]

I dont know your data distribution, however regarding a sample based on specific value look at pics and also added the job:

Note: wijk is dutch for area

examplejob_forversion_TOS_BD_v7.zip