Re: Natural keys vs Aritficial Keys

paul c <toledobythesea_at_oohay.ac> wrote:

>The so-called 'natural' key for all the airwaybills in a ULD on a
>typical airline flight segment is about seven or eight attributes. When
>the cargo master, at the last minute, offloads a container or two onto
>the tarmac, you don't want a ponderous logic to un-assign it and put it
>on the plane at the next gate. You need a form of indirection, for that
>matter the same is needed in any robotic application such as a freight
>warehouse.

Preumably though there are bar codes on the cargo containers and a simple form where the cargo master can remove selected containers from the airplane.

A welding shop client that empoyed hundreds of welders built and assembled very complex piping assemblies for refineries, power plants and oil sands plants. These are designed to, usually, fit on a 50' flat bed trailer. The client number could be in excess of 20 or 25 characters. The internal number they used went from 1 to whatever. It in turn was prefixed with a job number which started at 1 and went to whatever. The system printed multiple weather proof tag with the internal number as well as the bar coded long client number.

(Occasionally they would have to rebuild a particular item. The gravel pad at one client where these are stored is about a mile square. Well, if the plant has a large expansion, and there's a lot of snow that winter, you can't find the assemblies. Until the expansion is finished a year or two later and you're looking at the excess assemblies which are laying on the gravel.. And the folks at the plant getting paid $25 and $30 an hour love being told to go through all the items on this gravel pad looking for particular assemblies. A great way to spend a shift rather than hauling stuff around or whatever.)

Tony

-- 
Tony Toews, Microsoft Access MVP
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