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Re: indexi

  •  10-25-2006, 11:25 AM

    Re: indexi

    Deci sa inteleg ca o partitionare hash ar putea sa fie ca ceva de genu:

     

    --------------------------------------------------

    --modificarea structurii tabelului pentru a permite inserarea unei coloane,

    --calculata folosind o functie de hash simpla pe coloanele SECTIA si ANUNIV

    --------------------------------------------------

     

    ALTER TABLE Studenti_Note_Dub

    ADD HashResult INT

    GO

     

    --------------------------------------------------

    -- trebuie sa calculam rezultatul functie hash definita mai jos

    -- rezultat ce tebuie sa fie retinut in HashResult

    --------------------------------------------------

     

    UPDATE Studenti_Note_Dub SET HashResult =

                  (CAST(SECTIA AS INT) + CAST(ANUNIV AS INT)) % 2

    GO

     


    --------------------------------------------------

    -- definim functia si schema de partitionare in functie de coloana HashResult

    --------------------------------------------------

    CREATE PARTITION FUNCTION EvidScolStudentiNoteDubHASHPFN(INT)

    AS

           RANGE LEFT FOR VALUES (0, 1)

    GO

     

    --------------------------------------------------

    -- schema  este

    --------------------------------------------------

    CREATE PARTITION SCHEME [EvidScolStudentiNoteDubHASHPScheme]

    AS

           PARTITION EvidScolStudentiNoteDubHASHPFN  ALL TO ([PRIMARY])

    GO

     


    MCP (C Sharp)
    Software Engineer,
    Cluj Napoca
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