Re: update/insert, delete/insert efficiency WRT vacuum and

> > >Is there a difference in PostgreSQL performance between these two
> > >different strategies:
> > >
> > >
> > >if(!exec("update foo set bar='blahblah' where name = 'xx'"))
> > >    exec("insert into foo(name, bar) values('xx','blahblah'"); or

In pg, this strategy is generally more efficient, since a pk failing
insert would create
a tx abort and a heap tuple. (so in pg, I would choose the insert first
strategy only when
the insert succeeds most of the time (say > 95%))

Note however that the above error handling is not enough, because two
different sessions
can still both end up trying the insert (This is true for all db systems
when using this strategy).

Andreas