Percentage Sampling

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By specifying a rate, this transform reads in all of the data from the previous transform and generates a set of random indexes according to the rate input multiplied by the total record count.

Then it outputs the records according to those indexes.

Percentage Sampling
Percentage Sampling

1. Input

The Percentage Sampling transform requires 1 input transform that has at least 1 column.

The input could be a SQL Select transform, or the result of another transform. For example, the input data is:

Input Data
Input Data

2. Add the Transform

Steps to add the transform:

  1. Select the connector link.

    Adding the Percentage Sampling transform - Step 1
    Adding the Percentage Sampling transform - Step 1

  2. Select the transform from the menu.

    Adding the Percentage Sampling transform - Step 2
    Adding the Percentage Sampling transform - Step 2

  3. To Edit/Configue the transform, select the newly added transform, and click the Configure menu.

    Adding the Percentage Sampling transform - Step 3
    Adding the Percentage Sampling transform - Step 3

3. Configure

Steps to configure the Percentage Sampling transform:

Percentage Sampling transform configuration
Percentage Sampling transform configuration

  1. Sampling Percentage - Value, in terms of percentage of the input records, that you want included in the output.
  2. Random Seed - the number used to used to initialize a pseudorandom number generator.
    • Value is from 0 to 2,147,483,647.
    • If the value is 0, the random number generator uses the time and your random indexes will always be different.
  3. Select the columns to be included in the output.

4. Output

The figure below illustrates the output from the Percentage Sampling transform.

Percentage Sampling - partial output
Percentage Sampling - partial output

5. See also

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