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Please can anybody can correct me regrading the final result is non-empty or empty according to the query written and as per my knowledge, I know one thing that if there is nothing common then natural join degenerates into cross-product so I am getting not NULL relation / non-empty resultant set. and if I am wrong please give me the exact soln, Thanks in advance..

 

 

 

 

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Here, what we are doing is:

  1. Selecting values from table R where B<5
  2. Selecting values from table R where B>=5
  3. And then having a join amongst them.

Now, this condition can never occur, where we have a number that is less then 5 and also greater than or equal to 5.

So, it will return null set or empty output.

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