On Thu, Dec 20, 2012 at 3:28 AM, Robert James <srobertjames@gmail.com> wrote:
> Is there an aggregate that will return an arbitrary instance? That is,
> not necessarily the max or min, just any one? (Which might perform
> better than max or min)
>
> More importantly:
> Is there one which will return an arbitrary instance as long as it's not NULL
There's an extension on PGXN which implements first()/last()
aggregates in C: http://pgxn.org/dist/first_last_agg/
It should be slightly faster than min()/max(), but the difference is
probably not significant in more complex queries.
Regards,
Marti