Consider the relational algebra expression:

Assume that the join is based on the department identifier and that the condition Dept='CSE' refers only to attributes of DEPARTMENT. Which transformation is generally beneficial for reducing the number of tuples participating in the join?

Question

Consider the relational algebra expression: 
  
 Assume that the join is based on the department identifier and that the condition Dept='CSE' refers only to attributes of DEPARTMENT. Which transformation is generally beneficial for reducing the number of tuples participating in the join?

Accepted Answer

Push the department selection below the join, applying it to DEPARTMENT before joining

Answer

Replace the join with a Cartesian product.

Answer

Project away all join attributes before joining.

Answer

Perform the join first and apply both selections afterward.

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Consider the relational algebra expression: Assume that the join is based o...

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