Unique IDs, auto increment & wrap

[Adriano Nagelschmidt Rodrigues]

Hello,

I am looking for a good solution to create unique IDs in a table (entries will
be inserted concurrently by several clients). An ID should be a number less
than 1M, and can be reused after deleted.

I think an auto_increment column won't help here (1M boundary, won't
wrap). Or maybe I could use auto_increment % 1M as the ID (relying on the fact
that the number of rows at a given time is << 1M and there's no fragmentation
- oldest entries are batch processed and removed).

But maybe I'm overlooking a better solution... Any ideas?

Thanks,

--
Adriano