Percentage Sampling transformation in SSIS

It is similar to Row sampling but it gives the % output of the Source records. Suppose in source having the 600 records if we use 10% of row sampling then it will return the 60 rows but if we use row sampling then it will return the fix number of the row.

Let’s see the example of Row sampling

Open SSDT and take Data flow task

Double click on the Data flow task and the Data flow pane takes source as OLEDB

Now configure the required configuration of OLEDB Source

  

Click ok.

Now I am taking the percentage sampling

Double click on the transformation

Select the Percentage of rows which we want for sampling.

We can give the Sample output name as well as unselected rows (not sample).

Leave the Random seed check is unchecked. If we checked it then always it will show the same records.

Taking the Multicast to see the result

Select the sampling selected Output. Selected Unselected output is optional.

To seeing the result I am enabling the Data viewer.

Now it will be ready to run

See the total records on the table is 606 and the 10% sampling showing 69 (result will be variable so no worries)

Get the expected result.

Note

Percentage Sampling is full blocking transformation. If your source is OLEDB then it will be better to use sql and get the % rows from the backend .it will save the time. Performance will be increase.

It will good when you are using source as Flat files, CSV files.