Full Disjunction

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  • In this session we are going to talk about full disjunctions. Let’s get right to the point with a straight forward example for the usage and advantages of Full Disjunctions.
  • Full Disjunction

    1. 1. Full Disjunctions Credits for this presentation are due to my colleague Benny Kimelfeld. Itzhak Fadida Technion Israel
    2. 2. Example – Planning a tour When we plan a tour we wish to have the maximal information to help us make the correct choices.
    3. 3. Data Sources – Tourist Information Climates Accommodations Sites temperate UK tropical Bahamas diverse Canada Climate Country 3 Ramada London Canada Nassau Toronto City Hilton Plaza Hotel Bahamas 4 Canada Stars Country Buckingham London UK Mount Logan Canada London London City Hyde Park Air Show Site UK Canada Country
    4. 4. Natural Join – Providing Maximal Information SELECT * FROM ( Climates Natural Join Accommodations ) Natural Join Sites Air Show 3 Ramada diverse London Canada Site Stars Hotel Climate City Country
    5. 5. Natural Outer Join – Preserving Information temperate UK Mount Logan Canada 4 Plaza diverse Toronto Canada SELECT * FROM ( Climates Natural Outer Join Accommodations ) Natural Outer Join Sites Hilton Tropical Nassau Bahamas Hyde Park London UK Buckingham London UK Air Show 3 Ramada diverse London Canada Site Stars Hotel Climate City Country
    6. 6. Tourist Example – Full Disjunctions SELECT * FROM FD( Climates , Accommodations , Sites ) Site Stars Hotel Climate City Country Hilton tropical Nassau Bahamas Hyde Park temperate London UK Buckingham temperate London UK Mount Logan diverse Canada Air Show 3 Ramada diverse London Canada 4 Plaza diverse Toronto Canada
    7. 7. The Natural Join Operator Climates Accommodations Sites Climates Accommodations Sites A join tuple corresponds to a set of source tuples Join consistent Connected No Cartesian product Complete One tuple from each relation Stars Hotel Climate City Site Country temperate UK tropical Bahamas diverse Canada Climate Country 3 Ramada London Canada Nassau Toronto City Hilton Plaza Hotel Bahamas 4 Canada Stars Country Buckingham London UK Mount Logan Canada London London City Hyde Park Air Show Site UK Canada Country Air Show 3 Ramada London diverse Canada
    8. 8. Natural Join Misses Information Climates Accommodations Sites Bahamas is not in Sites , so natural join misses it temperate UK tropical Bahamas diverse Canada Climate Country 3 Ramada London Canada Nassau Toronto City Hilton Plaza Hotel Bahamas 4 Canada Stars Country Buckingham London UK Mount Logan Canada London London City Hyde Park Air Show Site UK Canada Country
    9. 9. Natural Join Misses Information Climates Accommodations Sites Bahamas is not in Sites , so natural join misses it Mount Logan is not in a city, hence missed A looser notion of join is needed — one that enables joining tuples from some of the tables temperate UK tropical Bahamas diverse Canada Climate Country 3 Ramada London Canada Nassau Toronto City Hilton Plaza Hotel Bahamas 4 Canada Stars Country Buckingham London UK Mount Logan Canada London London City Hyde Park Air Show Site UK Canada Country
    10. 10. Why and What is Full Disjunctions? <ul><li>The full-disjunction operation is a variation of the join operator that maximally combines join consistent tuples from connected relations, while preserving all information in the relations. </li></ul>
    11. 11. An Example of a Full Disjunction Climates Accommodations Sites FD ( R ) R temperate UK diverse Canada Climate Country 3 Ramada London Canada Toronto City Plaza Hotel 4 Canada Stars Country Buckingham London UK Mount Logan Canada London City Air Show Site Canada Country Stars Hotel Climate City Site Country
    12. 12. An Example of a Full Disjunction Climates Accommodations Sites FD ( R ) R temperate UK diverse Canada Climate Country 3 Ramada London Canada Toronto City Plaza Hotel 4 Canada Stars Country Buckingham London UK Mount Logan Canada London City Air Show Site Canada Country Stars Hotel Climate City Site Country 4 Plaza Toronto diverse Canada
    13. 13. An Example of a Full Disjunction Climates Accommodations Sites FD ( R ) R temperate UK diverse Canada Climate Country 3 Ramada London Canada Toronto City Plaza Hotel 4 Canada Stars Country Buckingham London UK Mount Logan Canada London City Air Show Site Canada Country Stars Hotel Climate City Site Country 4 Plaza Toronto diverse Canada Air Show 3 Ramada London diverse Canada
    14. 14. An Example of a Full Disjunction Climates Accommodations Sites FD ( R ) R temperate UK diverse Canada Climate Country 3 Ramada London Canada Toronto City Plaza Hotel 4 Canada Stars Country Buckingham London UK Mount Logan Canada London City Air Show Site Canada Country Stars Hotel Climate City Site Country 4 Plaza Toronto diverse Canada Air Show 3 Ramada London diverse Canada Mount Logan diverse Canada
    15. 15. An Example of a Full Disjunction Climates Accommodations Sites FD ( R ) R temperate UK diverse Canada Climate Country 3 Ramada London Canada Toronto City Plaza Hotel 4 Canada Stars Country Buckingham London UK Mount Logan Canada London City Air Show Site Canada Country Stars Hotel Climate City Site Country 4 Plaza Toronto diverse Canada Air Show 3 Ramada London diverse Canada Mount Logan diverse Canada Buckingham London temperate UK
    16. 16. An Example of a Full Disjunction Climates Accommodations Sites FD ( R ) R temperate UK diverse Canada Climate Country 3 Ramada London Canada Toronto City Plaza Hotel 4 Canada Stars Country Buckingham London UK Mount Logan Canada London City Air Show Site Canada Country Stars Hotel Climate City Site Country 4 Plaza Toronto diverse Canada Air Show 3 Ramada London diverse Canada Mount Logan diverse Canada Buckingham London temperate UK
    17. 17. Any Questions?

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