Package org.apache.accumulo.core.client.sample

Class RowSampler

java.lang.Object

org.apache.accumulo.core.client.sample.AbstractHashSampler

org.apache.accumulo.core.client.sample.RowSampler

All Implemented Interfaces:

Sampler

public class RowSampler
extends AbstractHashSampler

Builds a sample based on entire rows. If a row is selected for the sample, then all of its columns will be included.

To determine what options are valid for hashing see AbstractHashSampler. This class offers no addition options, it always hashes on the row.

To configure Accumulo to generate sample data on one thousandth of the rows, the following SamplerConfiguration could be created and used to configure a table.

 
 new SamplerConfiguration(RowSampler.class.getName()).setOptions(
   Map.of("hasher","murmur3_32","modulus","1009"));
 
 

Since:

1.8.0

Field Summary

Fields inherited from class org.apache.accumulo.core.client.sample.AbstractHashSampler

REQUIRED_SAMPLER_OPTIONS

Constructor Summary

Constructors

Constructor	Description
RowSampler()

Method Summary

Modifier and Type	Method	Description
protected void	hash(DataOutput hasher, Key k)	Subclass must override this method and hash some portion of the key.

Methods inherited from class org.apache.accumulo.core.client.sample.AbstractHashSampler

accept, init, isValidOption, validateOptions

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

RowSampler

public RowSampler()

Method Details

hash

protected void hash(DataOutput hasher,
 Key k)
             throws IOException

Description copied from class: AbstractHashSampler

Subclass must override this method and hash some portion of the key.

Specified by:

hash in class AbstractHashSampler

Parameters:

hasher - Data written to this will be used to compute the hash for the key.

Throws:

IOException