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CS4221 Project

P04. CS4221 Project . Implement Bernstein’s algorithm. He Jingxiao ( A0087637N ) LeNhat Minh ( A0074403N ) Wang Zihao ( A0073222U ) Wu Shitong ( A0070050B ). Why do we need a CASE tool ?. Fast way to extract relations schema based on given functional dependencies.

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CS4221 Project

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  1. P04 CS4221 Project Implement Bernstein’s algorithm He Jingxiao ( A0087637N) LeNhat Minh ( A0074403N ) Wang Zihao ( A0073222U ) Wu Shitong ( A0070050B )

  2. Why do we need a CASE tool ? • Fast way to extract relations schema based on given functional dependencies. • Display the results of each decompose step.

  3. Web Application Tool

  4. Front-end • GUI & API • Server : http://54.251.192.210/index.php/bernstein/ • Language : PHP, JavaScript, html

  5. Input • Users input functional dependencies.

  6. Back-end • Perform normalization and synthesizing to 3rd normal form following Bernstein's algorithm: • Step 1: Eliminate extraneous attributes. • Step 2: Finding covering. • Step 3: Partition. • Step 4: Merge equivalent keys. • Step 5: Eliminate transitive dependencies • Step 6: Construct relations. • Language used : Java

  7. Back-end ( Enhancements in Bernstein’s algorithm) • Shortcoming 1: Bernstein’s algorithm does not guarantee reconstructibility (or losslessness). Output of example 3:

  8. High level logic to add new relation with key and loss attributes • 1. Find all the attributes from the previous relations • 2. Compare the attributes from last step with the original full attributes to retrieve the loss attributes • 3. Create a new Relation with any key and loss attributes

  9. Back-end ( Enhancements in Bernstein’s algorithm) • Shortcoming 2: Bernstein's algorithm does not always find all the keys

  10. High level logic to find all the keys • Find all the attributes • Get every combination of attributes • Check if the closure of the combination is all the attributes • Retain only keys

  11. Result Results are then fed back to the frond end

  12. THANK YOU

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