compare the data using Toad ToolBar, Tools --> Compare Data

Hi..,
I have tried to "compare the data"(Using Toad ToolBar, Tools --> Compare Data) using a particular table which is available in two different schemas(these two are related to same project, but these are created using the different date related backups)
When there is granted the Roles Connect, Resource,DBA to these two schemas am able to take the "Compare Data"
When I have removed the DBA role from these two schemas, then am unable to "Compare the Data"
Can you please tell me here which privilege(/s) is/are required to grant instead of granting the DBA role.

Thanks in Advance
Giri K.Y.