Natural keys vs Aritficial Keys

#81

On Jul 3, 3:19*am, "Walter Mitty" <wami... (AT) verizon (DOT) net> wrote:

Quote:

"Roy Hann" <specia... (AT) processed (DOT) almost.meat> wrote in message

news:982dnVavb_XQM9DXnZ2dnUVZ8oGdnZ2d (AT) pipex (DOT) net...

My point is that the rows are logically duplicate but they have been
rendered spuriously distinct by tacking on a meaningless but unique
attribute. *So such an update is easy (perhaps inevitable).

This is an enormously important point, one that gets overlooked time and
time again in the discussion of databases.

Oh, I think I understand the point now. Indentical duplicates are
preferable to spuriously distinct rows. With identical duplicates, you
know you have duplicate data, and it stays that way. With spuriously
distinct rows, you may not become aware of their spurious nature
without non-trivial scrutiny.

Correct?

#82

lawpoop wrote:

Quote:

On Jul 3, 3:19*am, "Walter Mitty" <wami... (AT) verizon (DOT) net> wrote:
"Roy Hann" <specia... (AT) processed (DOT) almost.meat> wrote in message

news:982dnVavb_XQM9DXnZ2dnUVZ8oGdnZ2d (AT) pipex (DOT) net...

My point is that the rows are logically duplicate but they have been
rendered spuriously distinct by tacking on a meaningless but unique
attribute. *So such an update is easy (perhaps inevitable).

This is an enormously important point, one that gets overlooked time and
time again in the discussion of databases.

Oh, I think I understand the point now. Indentical duplicates are
preferable to spuriously distinct rows.

Well, in the sense that identical duplicates can be detected and
flagged, yes, a detectable problem is preferable to an undetectable one.

Quote:

With identical duplicates, you
know you have duplicate data, and it stays that way.

Knowing you have duplicates is better than not even being able to
tell you have duplicates, yes. And keeping them duplicate is better
too, because once you mutate one or all of them, you then have
ambiguities, with no logical basis to prefer one over any other. Then
you really would be screwed!

Quote:

With spuriously
distinct rows, you may not become aware of their spurious nature
without non-trivial scrutiny.

Correct?

Spot on!

--
Roy

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Natural keys vs Aritficial Keys

comp.databases.theory comp.databases.theory

Re: Natural keys vs Aritficial Keys - 07-06-2009 , 10:03 AM

Re: Natural keys vs Aritficial Keys - 07-06-2009 , 12:21 PM