Re: Primary keys and composite unique keys(basic question)

On 4/7/21 11:35 AM, Rob Sargent wrote:

On Apr 7, 2021, at 10:17 AM, Ron <ronljohnsonjr@gmail.com> wrote:

 On 4/5/21 9:37 PM, Rob Sargent wrote:

It's a small thing, but UUIDs are absolutely not memorizable by
humans; they have zero semantic value.  Sequential numeric identifiers
are generally easier to transpose and the value gives some clues to
its age (of course, in security contexts this can be a downside).

I take the above as a definite plus.  Spent too much of my life correcting others’ use of “remembered” id’s that just happened to perfectly match the wrong thing.

People seem to have stopped appending check digits to identifiers about 20 years ago, and I'm not sure why.

No the problem is “start from one”. User has item/I’d 10875 in hand and types in 10785 which of course in a sequence supplied ID steam is perfectly valid and wrong.  Really hard to track down.

That's my point.  Adding a check digit (turning 10875 into 108753) would have caught that, since 107853 does not match 107854 (which is 10785 with a check digit added).