Message-Id: <26007.339521@fatcity.com>
From: orababy <orababy@mail15.com>
Date: Fri, 25 Jul 2003 12:12:34 +0400 (MSD)
Subject: Re: "data is skewed" - what does it mean ?

Oh...

Thank U Mark.

got it now.

...now i can explain it to someone who doesn't know.

Cheers.

 Mark Richard <mrichard@transurban.com.au>:
> It's not this simple...
> Let's take your low cardinality example...  Gender is a good 
example since
> there are only two (common) genders - male and female.
> A table with 10,000 staff would make the gender column low 
cardinaility -
> only 2 distinct values.  If you had 5,000 males and 5,000 
females then the
> data would be evenly distributed and therefore not skewed.  If, 
however,
> you had 9,500 females and 500 males then you have skewed data.
> Hopefully this gives some idea of the difference between 
cardinality and