Re: Database design, Keys and some other things


"-CELKO-" <jcelko212@xxxxxxxxxxxxx> wrote in message
news:1127914182.462827.172910@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Dr. Codd: "..Database users may cause the system to generate or delete
> a surrogate, but they have no control over its value, nor is its value
> ever displayed to them ..."(Dr. Codd in ACM TODS, pp 409-410) and Codd,
> E. (1979), Extending the database relational model to capture more
> meaning. ACM Transactions on Database Systems, 4(4). pp. 397-434.

> This means that a surrogate ought to act like an index; created by the
> user, managed by the system and NEVER seen by a user. That means never
> used in queries, DRI or anything else that a user does.

I understood that the VALUE of the SURROGATE cannot be seen and controlled,
not the SURROGATE. Are the VALUE and the SURROGATE the same thing ?



.

Relevant Pages

  • Re: Traversing large data table
    ... "..Database users may cause the system to ... nor is its value ever displayed to them ..."(Dr. Codd in ACM TODS, ... What part of "no control over" and "nor ever ... To me this means that a surrogate ought to act like an index; ...
    (microsoft.public.sqlserver.programming)
  • Re: [NOW ANSWER Aarons QUESTION CELKO]
    ... True surrogates are fine; ... surrogate keys Dr. Codd was refering to when he wrote: ... Codd in ACM TODS, pp 409-410) and Codd, E., Extending the ... database relational model to capture more meaning. ...
    (microsoft.public.sqlserver.programming)
  • Re: Traversing large data table
    ... > generate or delete a surrogate, but they have no control over its value, ... > nor is its value ever displayed to them ..."(Dr. Codd in ACM TODS, ...
    (microsoft.public.sqlserver.programming)
  • Re: How should I generate a primary key?
    ... the external reality and verify them. ... be verified for syntax or check digits inside itself. ... A surrogate key is system generated to replace the actual key behind ... with a quote from Dr. Codd: "..Database users ...
    (comp.databases)
  • Re: Guidelines to a decent support of surrogate key implementation
    ... totally unrelated to the logical data model. ... A surrogate key is system generated to replace the actual key ... with a quote from Dr. Codd: ... Extending the database relational model to capture more meaning. ...
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