Sample

Overview

Using the Sample tool, you can extract a "representative" subset of a table—that is, the resulting table will tend to have the same statistical distribution of field values as the original table. This is useful for:

• Examining the results of a process without wading through all the records.

• Extracting a statistical sample of a telephone list for surveys.

• Extracting a sample of a database for further statistical processing.

The Sample tool reads one in every N records, where N is a number you specify. If you want to start at a particular record, you can also specify the starting record number. For example, if you have a static data set, and want to pull a different sub-sample every week, you would increment the starting record each time you pulled a new sample.

Sample tool configuration parameters

The Sample tool has one set of configuration parameters in addition to the standard execution options.

Parameter	Description
Sample rate	Sampling frequency. Defaults to 1, sampling every record. Must be between 1 and 1,000,000,000.
Skip first N	Starting record for the sample. Defaults to zero (0). Note that the first record of the table is one (1). Must be between 1 and 1,000,000,000.

Configure the Sample tool

1. Select the Sample tool.

2. Go to the Configuration tab on the Properties pane.

3. Enter the sampling frequency in the Sample rate box. For example, a Sample rate of 20 samples one of every 20 records. Must be between 1 and 1,000,000,000.

4. Optionally, specify the starting record number in the Skip first N box. Must be between 0 and 2,000,000,000.

The first record of any table is 1. For example, if you set Skip first N to 2, the starting record will be 3.

4. Optionally, go to the Execution tab, and then set Web service options.