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javahadoopaccumulo

I am looking at writing an Accumulo iterator to return a random sample of a percentile of a table

I am looking at writing an Accumulo iterator to return a random sample of a percentile of a table.

I would appreciate any suggestions.

Thnaks,

Chris

Solution

  • You can extend org.apache.accumulo.core.iterators.Filter and randomly accept x% of the entries. The following iterator would randomly return 5 percent of the entries.

    import java.util.Random;

import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.core.data.Value;
import org.apache.accumulo.core.iterators.Filter;

public class RandomAcceptFilter extends Filter {
    private Random rand = new Random();

    @Override
    public boolean accept(Key k, Value v) {
        return rand.nextDouble() < .05;
    }
}