Is there anyway to compare the contents of tables on two different TD instances? For example what if we wanted to compare teh data in table abc on prod with table abc on Test in one query, is there anyway we can do that?
I will not suggest you have entries in both prod and test :). Anyone in that case can tamper costly production data. You can take the prod data thru fastexport and then fload to test and then do a sanity comparison. It is safe. Also you can ask the DBA to port the data from prod to test as per his suggestions.
There are other ways to compare too like using excel sheet if data volume is low.