On 7/8/05, Rod Taylor <pg(at)rbt(dot)ca> wrote:
> Create 2 sequences, one for counting tuple additions and one for
> counting tuple deletions.
> 
> When you INSERT a tuple, bump the "added" sequence (select nextval());
> 
> When you DELETE a tuple, bump the "deleted" sequence (select nextval());
> 
> To retrieve an approximate count, take the current value of both
> sequences (select directly -- don't use currval) and subtract the
> "deletes" from the "adds".
Never thought of that!  Good idea. :-)
   Regards,
      Dawid
PS: There aren't any on ROLLBACK triggers, right? ;-)))