RE: Need ideas for SQL join select to replace logical view

["Wilt, Charles" <WiltC@xxxxxxxxxx>]

> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx 
> [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Joe Pluta
> Sent: Sunday, September 16, 2007 9:57 AM
> To: 'Midrange Systems Technical Discussion'
> Subject: RE: Need ideas for SQL join select to replace logical view
>
>
> You are suggesting storing the same information in two 
> records.  Your end time of one event is the same as the start 
> time of the next event.  That's by definition not normalized 
> data, and thus non-relational in nature.  


Joe,

Not sure I agree with this.

There's a difference between storing the same data in two places, and storing two separate pieces of
data that happen to have the same value.

As I see it, start time and end time are two different pieces of information.  In the OP's case, a
given start time happens to match a the prior records end time.  I don't see that as violating
normalization rules.

Actually, given that BETWEEN is inclusive as you pointed out, I'd considering setting this up so that
the end time didn't match the next start time. Instead, the start time would be 1 mircosecond greater
than the last end time.


Charles


This e-mail transmission contains information that is intended to be confidential and privileged.  If you receive this e-mail and you are not a named addressee you are hereby notified that you are not authorized to read, print, retain, copy or disseminate this communication without the consent of the sender and that doing so is prohibited and may be unlawful.  Please reply to the message immediately by informing the sender that the message was misdirected.  After replying, please delete and otherwise erase it and any attachments from your computer system.  Your assistance in correcting this error is appreciated.