The VFP9 help for sys(2015) says:
Calling SYS(2015) more than once during the same millisecond
interval returns a unique character string.
Meaning that the result will still be unique even though you call it
more than once in the same millisecond. I ran Paul's code in 3 seconds,
which generated 1 million strings and then compared them for duplicates.
My observations indicated that the generation took much less time than
the comparison, say on the order of 1 second. This would be 1000 calls
to sys(2015) per millisecond, and I encountered NO duplicates.
Personally, I'd rather use autoincrement, but I still don't see any
evidence that sys(2015) generates duplicates.
Dan Covill
On 08/27/12 17:34, Ken Dibble wrote:
> On 8/24/12 7:18 PM, Ken Dibble wrote:
>>>> > >> >There are no guarantees in life. But the danger of sys(2015) lies in
>>it's
>>>> > >> >generation
>>>> > >> >based on the timestamp. What are the chances of collision on this
>>even not
>>>> > >> >concatenating the machine name?
>> > >Somewhat high, I believe. System clock ticks <> processor cycles. As I
>> > >understand it, in VFP RAND() uses the system clock, and RAND() will
>> > >generate the same number over and over and over in a tight loop on a fast
>> > >machine, until the system clock ticks over.
>>
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