Re: AVG_ROW_LEN inaccurate?

Apart from Brian's comment on vsize, you also have to remember that trailing nulls (i.e. blanks at the end of the row) take up no space at all - not even a length byte.

For most purposes, vsize + 1 is good
enough for most columns, then add
5 (two for the overhead, one for the
used column count, and two for the
row directory entry) is a good enough
approximation - especially if you only
sample a small percentage of the rows
anyway.

--
Jonathan Lewis
Yet another Oracle-related web site:  http://www.jlcomp.demon.co.uk

Practical Oracle 8i:  Building Efficient Databases

Publishers:  Addison-Wesley
See a first review at:
http://www.ixora.com.au/resources/index.htm#practical_8i
More reviews at: http://www.jlcomp.demon.co.uk/book_rev.html



John Dorlon wrote in message
<5k166.6705$ge4.3760840_at_news2.rdc2.tx.home.com>...


>Thanks Jonathan.

>

>  Funny that VSIZE does not include that.  Is there another function that

>does, or do I just have to add

>some decodes in my query to get the 1 or the 3 added in?

>

>-John

>

>