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

I want to say thanks to Joe, Steve and Chuck for the input. I am learning
a lot!

I think Charles's suggestion of linking the owner record to the inventory
status record missed the notion that the timestamp ownership begins for an
inventory item is in the OWNER table. To make it work both I_CONTROL# and
I_OWERID would be used together to find the owner record.

I_STATUS represent a set of status information about an inventory item.

O_OWNER represents a set of owner information about an inventory item.

Cars and people were used as example of inventory and owner because it is
a useful analogy.

An inventory item goes through several states of status in its life,
several records per I_CONTROL# in the inventory table.

An inventory item has few owners in its life, often as few as one.

Chuck, the idea to put a date range in the OWNER record makes a lot of
sense. It may not be practical to change data base design at this point
but one should always look at all aspects of the problem.

Joe, you are probably correct. I did kill the query after it had run a
few minutes. The file has 1,450,000 inventory records and 730,000 owner
records.

Steve, I'll try out your suggestions today.

Again, thanks for the different approaches to this problem!

Bill Blalock





"Wilt, Charles" <WiltC@xxxxxxxxxx>
09/17/2007 08:17 AM
Please respond to Midrange Systems Technical Discussion

To: Midrange Systems Technical Discussion
<midrange-l@xxxxxxxxxxxx>
cc: (bcc: Bill Blalock/TUS/US/Certegy)
Subject: RE: Need ideas for SQL join select to replace
logical view


Actually,
As I think about it, a more relational way to do this would be to simply
have an OWNER_ID, in the
Inventory table.
Why? Simple, given the current structure, if the same person owns
multiple cars, not only are you
duplicating data but you don't really know that the same person has two
cars.
INVENTORY A table
I_CONTROL#
I_STATUS (really a lot of information)
I_TMSP
I_OWNERID
OWNER B table
O_OWNERID
O_OWNER

Charles

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Wilt, Charles
Sent: Monday, September 17, 2007 8:51 AM
To: Midrange Systems Technical Discussion
Subject: RE: Need ideas for SQL join select to replace logical view

-----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.

--
This is the Midrange Systems Technical Discussion
(MIDRANGE-L) mailing list To post a message email:
MIDRANGE-L@xxxxxxxxxxxx To subscribe, unsubscribe, or change
list options,
visit: http://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxx Before posting,
please take a moment to review the archives at
http://archive.midrange.com/midrange-l.

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.