Run a query in the Editor.
Right click on data grid and Send To | Report Data Designer
Save the report (.tdr)
Go to Data tab and make a change to the query ( do not execute the new query)
Go to File | Save File
Close the Report Designer
Now re-open the .tdr report
The change to the SQL will not apply
However, if a change is made to the query in the Data Report (in the Data tab) AND it is executed, this results in a looping message:
"You have changes in your SQL that have not been applied. Would you like to apply them now and update the data?"
If 'YES' is clicked then the message comes up again. 'NO' or 'CANCEL' stops the looping and Toad does recognize that a change has been made (denoted by the * beside the file name). At this point if it's saved, then the changes will be applied.