I believe you get this effect because
oracle generates a random set of
rowids - and some of the rows don't
exist.
--
Regards
Jonathan Lewis
http://www.jlcomp.demon.co.uk
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The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html
"Telemachus" <telemachus_at_ulysseswillreturn.net> wrote in message
news:x709a.245$pK2.506_at_news.indigo.ie...
>
>
> The Concepts and the SQL Ref aren't too clear on this.
>
> I' like to know if SAMPLE is or is not guaranteed to return exact
numbers.
>
> I have a test table with 1,000,000 rows and issue a 50% sample
clause
> Are the over/under results I'm getting acceptable i.e. SAMPLE not
guaranteed
> to be exact or to within a specific percentage?
>
>
> The docs (Metalink 95455.1) says of the SAMPLE option "reads a
specified
> percentage and
> <...> examines it to see whether it satisfies the where clause "
>
Received on Tue Mar 04 2003 - 09:54:22 CST
