Re: Is the use of VARCHAR(256) as Primary Keys preferred in Oracle?

Mark.Powell_at_eds.com (Mark D Powell) wrote in message news:<2687bb95.0212050801.2ed54cd4_at_posting.google.com>...
> Galen Boyer <galenboyer_at_hotpop.com> wrote in message news:<ulm3b1sbt.fsf_at_hotpop.com>...
> > On 27 Nov 2002, Mark.Powell_at_eds.com wrote:
> > > Galen Boyer <galenboyer_at_hotpop.com> wrote in message
> > > news:<uwumzph80.fsf_at_hotpop.com>...
> > >
> > > key has to be associated to the correct business data. In examples
> > > like this that association is subject to errors.
> >
> > Mark,
> >
> > I guess the SSN isn't all that great of an argument tool for the
> > "natural" crowd? Do many people actually choose to use the SSN as a
> > key? I would never do this because of the simple fact that there would
> > be too many rules played out before the record got into the database.
> > Is the "key" in a particular format?
> > Does it have only numbers?
> > Is there a 10th digit?
> > Is it really the correct SSN number?
> > ...
> >
> > I would rather make it so there is more than one way to identify the
> > person on the end of the app, allowing for mistakes at each entry point,
> > hoping they can at least remember one way in. If they do get one of
> > those correct, then they get the information from the record with my
> > manuafactured key.
> >
> > Having the key to the table be something that the user is in charge of
> > defining doesn't sit well with me.
>
> Galen, sorry about the slow response. I missed checking on my threads
> due to American holiday and busy days at start of month but to try to
> answer some of your questions.
>
> Yes, the SSN is often used as a key on mainframe payroll/benefit
> systems. I do not have much experience working with these systems but
> back around 1992 I helped move data from one version of such a system
> to another and it used the 9 digit SSN as a unique key.
>
> I talked to friend at a college and their system appends another 9
> characters to the SSN for the system key, but she said they have a
> unique secondary index on the SSN and that is used for access for most
> of the time.
>
> And importantly the the first character of the SSN may be a
> non-numeric nowdays. She says they have entries that start with a
> 'D', but she doesn't know of any special meaning being attached. She
> also believes that the SSN can be 10, but their system was setup years
> ago to handle 13 digits. I suspect someone had realized that the
> Social Security people were going to run out of numbers and just
> expected them to get bigger.
>
> I have seen a lot of screens that use the SSN when dealing with
> collegs and the health insurance systems seem to use SSN as their
> primary means of access.
>
> This dependence on one number, the SSN, is the main reason we have an
> Identify theft problem here in the US. It is an easy crime to commit.
> Most consumer financial systems seem to identify the consumer by the
> SSN.
There is an additional consideration, and that is, in many cases it is illegal to _require_ SSN as an identifier (well, not really, see http://www.eref.net/privacy/fact_sheets/protecting_ssn.asp , although that ignores some court decisions). I know at least one person who is very principled and will refuse to give it unless shown regulations that permit it. Also, some groups consider it a religious affront, and are definitely not required in most circumstances.

See various archives like comp.risks and privacy.org for more details.

http://www.ucan.org/law_policy/teledocs/ssnwire.html

>
> HTH -- Mark D Powell --

jg

--
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