Skewed columns
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Thread: Skewed columns

  1. #1
    Join Date
    Feb 2006
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    162

    Skewed columns

    In creating histograms,i read a term called "skewed data columns",Can anyone explain me what does it mean in detail with an example?

    Thanks,
    Malru

  2. #2
    Join Date
    Sep 2002
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    why dont you look it up in the docs, where it is explained?

    tahiti.oracle.com

  3. #3
    Join Date
    Feb 2006
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    It's explained in any doc,thats why i'm posting here.If you know,please explain.what exactly skewed column,means.

    Thanks,
    Malru

  4. #4
    Join Date
    Apr 2001
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    Bangalore, India
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    Code:
    SQL> create table emp (ename varchar2(50), esex varchar2(10));
    
    Table created.
    
    SQL> insert into emp select object_name,'Male' from dba_objects;
    
    9369 rows created.
    
    SQL> commit;
    
    Commit complete.
    
    SQL> insert into emp select object_name,'Female' from dba_objects where rownum < 20;
    
    19 rows created.
    
    SQL> commit;
    
    Commit complete.
    
    SQL> select esex,count(*) from emp
      2  group by esex;
    
    ESEX         COUNT(*)
    ---------- ----------
    Female             19
    Male             9369
    Thats it.
    Last edited by Thomasps; 05-15-2006 at 03:15 AM.
    Thomas Saviour(royxavier@yahoo.com)
    Technical Lead (Databases)
    Thomson Reuters (Markets)

    http://ora600tom.wordpress.com/

  5. #5
    Join Date
    Feb 2006
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    Thanks Thomasps,

    Can you please explain this example because i didn't understand anything by this example?

  6. #6
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    Kindly read the oracle Docs or books from Tom Kyte and raise your dobts.
    Thomas Saviour(royxavier@yahoo.com)
    Technical Lead (Databases)
    Thomson Reuters (Markets)

    http://ora600tom.wordpress.com/

  7. #7
    Join Date
    Feb 2006
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    I'm new to dba(self-learning),thats why i'm posting a lot here.

    I read about skewed columns in Oralce docs only & searched in net also,but nowhere explained clearly what is skewed column,thats why i posted it hear,you've given an example,what is difficulty in explaining this,please explain it.

  8. #8
    Join Date
    Apr 2001
    Location
    Bangalore, India
    Posts
    727
    Ok. Read this.

    http://asktom.oracle.com/pls/ask/f?p...A:707586567563

    http://asktom.oracle.com/pls/ask/f?p...34807121420113

    After reading explain me what is skewness? All the best
    Thomas Saviour(royxavier@yahoo.com)
    Technical Lead (Databases)
    Thomson Reuters (Markets)

    http://ora600tom.wordpress.com/

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