Need quey for update large database fastly

Beantwortet Need quey for update large database fastly

  • Montag, 4. März 2013 05:58
     
     

    Hi,

    currently i have a table with 80 crore rows data ,I need to obfucate the data in some columns for eg:-If name is 'David Peter' (Same name is used in differnet rows),then i need to update it with some other values like 'ytfr trey'.Now what we do is we have a table with column data like  'ytfr trey' and we are updating randomly the in the table based on rownumber function but this take so much of time .So what i need is a sql query having the logic to update like this eg:-If ABCD is name then i need to update it with CDEF ie two letter difference or some different name but query should update data fastly

    Regards

    Jon

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  • Montag, 4. März 2013 09:39
     
     Beantwortet

    Hi - maybe its the 'order by' part of the row_number which is causing the overhead...

    Have a look in the estimated execution plan ot the query (CTRL + L) and see if the 'sort' is taking a larger percentage

    you could replace the order by seciton of rownumber with order by (select null) instead if the ordering is not actually important.

    Just an idea ...


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