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Thread: Relational algebra

  1. #1
    Join Date
    Jun 2012
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    2

    Relational algebra

    Untitled2.jpg

    Brain Teaser!!

    I have two example tables R,S as seen above, I want to write a query that returns all attributes A (left table) that are associated with exactly 'b2' and 'b4' from the other table, in this case it should return only a2.

    Using division returns both a1 and a2 since they both have that association, but a1 does not apply since it has association with other attributes, only allowed to use minimal relational algebra operators

  2. #2
    Join Date
    Jun 2012
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    2
    http://i.stack.imgur.com/Z0Bbg.jpg
    if the image is not visible here is the link:
    http://i.stack.imgur.com/Z0Bbg.jpg

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