In this blog entry I am going to outline the function of the Column Null Ratio profile request in the new Data Profiling Task in SQL Server 2008. BOL states about this profile request:
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Reports the percentage of null values in the selected column.
This profile helps you identify problems in your data, such as an unexpectedly high ratio of null values in a column. For example, you profile a Zip Code/Postal Code column and discover an unacceptably high percentage of missing codes. |
I have tested it out on the [Person].[Contact].[MiddleName] column which looks like this:
As you can see, there's a fairly healthy distribution of NULL values in there. Below you can see the configuration of the Data Profiling Task which is checking the [Person].[Contact].[MiddleName] field for NULL values..
And here are the results:
Its fairly clear to see here how many NULL values there are in the column and what the percentage of rows that contain a NULL value is.
This concludes my brief summary of the Column Null Ratio profile request in the Data Profiling Task that is being introduced with SQL Server Integration Services 2008. For more posts in this series please refer to SSIS: Data Profiling Task: Part 1 - Introduction
-Jamie
Disclaimer: The information in this blog post is correct at the time of publication. It may have changed before SQL Server 2008 is released.