On Tue, Sep 24, 2013 at 11:03 AM, didier <did...@gmail.com> wrote: > Hi > > > On Tue, Sep 24, 2013 at 5:01 PM, <jes...@krogh.cc> wrote: > >> >> Apparently it is waiting for locks, cant the check be make in a >> "non-blocking" way, so if it ends up waiting for a lock then it just >> assumes non-visible and moves onto the next non-blocking? >> > > Not only, it's a reason but you can get the same slow down with only one > client and a bigger insert. > > The issue is that a btree search for one value degenerate to a linear > search other 1000 or more tuples. > > As a matter of fact you get the same slow down after a rollback until > autovacuum, and if autovacuum can't keep up... >
Have you experimentally verified the last part? btree indices have some special kill-tuple code which should remove aborted tuples from the index the first time they are encountered, without need for a vacuum. Cheers, Jeff
