RE: 'Theoretical' SQL question

[Alexei Pytel <pytel@xxxxxxxxxx>]

Well, your original question was - if there is a unique key and you are 
searching on "equal", how many records will be processed.
If it is unique key, then there is an index (there are no other ways to 
guarantee unique key).
If there is an index and you are searching on "equal", then from index in 
one step you get a list of values which match - one.
I still do not see an issue here.

    Alexei Pytel
speaking for myself




"Hall, Philip" <phall@xxxxxxxx> 
Sent by: midrange-l-bounces@xxxxxxxxxxxx
01/20/2005 07:37 PM
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RE: 'Theoretical' SQL question






> If the field is a unique key, it got to be an index.
> If it is an index, then table scan is not needed - so there is no issue.
> 
> Do I miss something here?
> 

Yes, my original question.

Which was can one assume _100%_ that the processing will stop once the 
record has been located.


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