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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
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why dont you look it up in the docs, where it is explained?
tahiti.oracle.com
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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
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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.
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Thanks Thomasps,
Can you please explain this example because i didn't understand anything by this example?
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Kindly read the oracle Docs or books from Tom Kyte and raise your dobts.
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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.
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