On Fri, Feb 17, 2012 at 1:21 PM, Andrew Dunstan <andrew@dunslane.net> wrote:
> Assuming we had the cast, What would "intval like '1%'" mean? You're going
> to match 1, 10..19, 100..199, 1000..1999 ...
>
> Now maybe there's a good use for such a test, but I'm have a VERY hard time
> imagining what it might be.
Well, I can readily see someone encoding parts of their application
into this sort of encoding, so that, for instance, all customer
numbers beginning with "1" are deemed to be "internal accounts."
It's a pretty terrible approach to encoding data for an application;
it leads to stuff like the "oops, once they have generated 30,000
invoices, the system reaches doomsday and can't work anymore."
http://thedailywtf.com/Articles/Ive-Got-Your-Number.aspx
But nothing prevents users from designing their applications to encode
information in their ID prefixes.
And I have *zero* confidence that for PostgreSQL to rule out "LIKE
'1%'" is preventing those designs from getting built...
When confronted by a difficult problem, solve it by reducing it to the
question, "How would the Lone Ranger handle this?"