Control Query in Web Templates

Hi Experts,

I was going through the Control Query document on help.sap.com. From the document I understood that, it is a help query that executes before the queries in the Web Template.

I have a document and also I know how to create this but,can anybody give me a scenario where I can use control query will be a great help for me.

Thanks in advance.

Regards,

-Ashish