Re: Could be improved point of UPSERT

In my example, I just give each record a different ID to access it
efficiently.

In our business cases, some times, we also use some prefix letter like
'SO', "PO' combining with the current year, month and then a sequence
to make a invoice ID,

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.

Regards,

Daojing Zhou.

On Wed, Jul 15, 2015 at 2:33 AM, Peter Geoghegan <pg(at)heroku(dot)com> wrote:

> On Sun, Jul 12, 2015 at 4:09 AM, Yourfriend <doudou586(at)gmail(dot)com> wrote:
> > Suggestion: When a conflict was found for UPSERT, don't access the
> > sequence, so users can have a reasonable list of ID.
>
> This is not technically feasible. What if the arbiter index is a serial PK?
>
> The same thing can happen when a transaction is aborted. SERIAL is not
> guaranteed to be gapless.
> --
> Peter Geoghegan
>