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

Karsten Farrell <kfarrell_at_belgariad.com> wrote:

> > That's the same as for OPS when you use CACHE and NOORDER. Each local
> > 'office' gets a chunk of numbers from which it allocates without
> > refering back to the central office. The only difference being how
> > large those chunks are and how many offices there are. Do you consider
> > Oracle sequence numbers to be natural for this reason?

> I don't see how the next set of cached sequence numbers is the same as
> the pre-assigned region number used in SSNs. Sequence numbers still
> increase in value. An SSN of 555-xx-xxxx can be assigned, followed by an
> SSN of 123-xx-xxxx. SSNs bounce all over the place. Sequence numbers
> don't.

Set the CACHE to 1,000,000 (assuming that's possible) and have >50 machines in your parallel server, and sequence numbers will bounce all over the place, too.

> And your point is? As stated above, Oracle sequence numbers do not
> contain any smarts; but SSNs do.

As stated above, that's false. Given equal knowledge of the details of implementations, they both contain the same smarts. Just at a different level of granularity. SSN which yield the same answer to int(SSN/1,000, 000) came from the same regional office (or used to) and sequence numbers that are the same after int(SEQ/CACHE-Offset) came from the same machine in a parallel server.

Xho

> > Xho
> >

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