Re: 1 Sequence per Row i.e. each customer's first order starts at 1

On Wed, Jul 1, 2009 at 7:46 PM, Merrick<merrick(at)gmail(dot)com> wrote:
> I was hoping there would be a way to add a field the sequence table
> postgresql automatically generates so I could rely on whatever
> mechanism postgresql uses to avoid the problems described thus far.
>
> I should have included more info, it's highly likely that multiple
> users will be accessing using same customer_id when creating orders
> thus deadlocks would be an issue I would like to avoid.
>
> Having the sequence be gapless would not be a requirement.

Hmmm. Well, are those users gonna be holding a lock while they do a
lot of hand processing work? Do they need that id before they start a
lot of complex work? In that case, you could do things two fold.
Lock the rows, create an empty but ready to go one, commit, then come
back later and update the row.