For the most cases I mentioned, we don't request a strict gapless sequence for the Invoice ID, the essential requirement is unique. We just hope that there is no obviously gap in most situations. >From the test of UPSERT, there are quite a few chances to generate a big gap when UPSERT multi records. However, the result of UPSERT is acceptable, and I do love this function. So, it's a suggestion only.
Anyway, thanks a lot for the detail explanation. Regards, Daojing Zhou. On Wed, Jul 15, 2015 at 3:23 PM, Peter Geoghegan <p...@heroku.com> wrote: > On Wed, Jul 15, 2015 at 12:01 AM, Yourfriend <doudou...@gmail.com> wrote: > > for example, SO201507_1001, PO201503_1280, etc. > > > > As these IDs would be the most important attribute to the business, so, > we > > hope there is no gap for the IDs. > > That's a requirement I've heard a number of times before. If you're > relying on a sequence for this purpose, your application is already > broken [1]. UPSERT need not be involved at all. > > [1] http://www.varlena.com/GeneralBits/130.php > -- > Peter Geoghegan >
