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Look for identical column in parallel database

  • October 31, 2007 at 4:05 am

    #180722

    Hi everybody,

    I compare two database in order to upgrad the oldest according to the newer,

    the both database need to store the same data ,henc, for the most part they consist same table and each table consist same column.

    To compare table or column,I'm using the table_name or column_name

    Though ,there is parallel column that have different names :crazy:

    Is anyone have an idea how can I figure out that two columns from two database serves for the same purpose.

    I know that I can compare there type or length, but its not satisfied ,I prefered somthing more injective

    Thanks

    Rachamim

  • October 31, 2007 at 4:14 am

    #746976

    There are many third party tools available in the market, such as SQL Compare from RedGate, SQLDiff from ApexSQL with 30 day free trial editions...

    --Ramesh

  • October 31, 2007 at 4:19 am

    #746978

    One possible way of doing this is to have a user defined function for "distance". In case of two numeric columns a difference/ratio (careful with nulls). And then have a query that calculates this distance for the possible column combinations.

    E.g. TableInDB1 (a int, b int, c int), TableInDB2 (a int, d int, e int) (based on the type similarities and the unmatched columns you can have a query that gets max distance(TableInDB1.b, TableInDB2.d), max distance(TableInDB1.c, TableInDB2.d), max distance(TableInDB1.c, TableInDB2.d), max distance(TableInDB1.c, TableInDB2.e)

    If any of these distance maximums/minimums are in a threshold range, then the column pairs are possibly parallel columns. This is a very simple approach (there are more complex ones), and it is resource intensive as well. However, it can be automated, so it saves you sitting in front of the computer 🙂

    Regards,

    Andras

    Andras Belokosztolszki, MCPD, PhD
    GoldenGate Software

  • October 31, 2007 at 4:23 am

    #746982

    well I know

    But in some reasons I need to do it myself.:crying:

    Rachamim

  • October 31, 2007 at 4:25 am

    #746983

    my last post intended to Ramesh

    the traffic here is very fast

  • October 31, 2007 at 4:44 am

    #746987

    Tanks Andres

    I going to try it

    Well as you said its "resource intensive as well" and I'll need to check out if the program can suffer the overhead of such solution

    Rachamim

  • October 31, 2007 at 6:35 am

    #747029

    but which parameter ,except column_type and length ,that usually identical, I can use to calculate distance?

    Rachamim

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