RE: 'Theoretical' SQL question

What would you expect?  Making the presumption that the optimizer has to 
perform a table scan, it doesn't know how many, or where, any matching records 
might be.  Resulting in the entire table being read.  It's no different than 
reading through an unsorted file with a program looking for records with a 
specific key.  I don't think it has anything to do with which database product 
you are using.

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx]On Behalf Of Hall, Philip
Sent: Thursday, January 20, 2005 3:41 PM
To: Midrange Systems Technical Discussion
Subject: RE: 'Theoretical' SQL question


Thanks for the info Kevin.

It's a sad state of affairs, and no wonder why SQL Server simply out performs 
both DB2 and Oracle...

--phil

> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-
> bounces@xxxxxxxxxxxx] On Behalf Of Kevin Wright
> Sent: Thursday, January 20, 2005 3:14 PM
> To: 'Midrange Systems Technical Discussion'
> Subject: RE: 'Theoretical' SQL question
>
> >From what I can work out it does even worse for WHERE RRN(CUSTOMERS) =
> 12345
> ... can you pronounce full table scan from rrn 1 to rrn last, not stopping
> at 12345 ... and apparently IBM is not going to improve it.
>
> Kevin Wright


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