Re: sequence indexes

Justin Clift wrote:
>
> Tom Lane wrote:
> >
> > "Zeugswetter Andreas SB SD" <ZeugswetterA(at)spardat(dot)at> writes:
> > >> I've looked at the problem a little bit --- there's literature more
> > >> recent than Lehmann-Yao that talks about how to do btree compaction
> > >> without losing concurrency. But it didn't get done for 7.2.
> >
> > > Yes, there must be. Informix handles this case perfectly.
> > > (It uses a background btree cleaner)
>
> As an idle thought, I wonder what other maintenance tasks we could have
> a process in the background automatically doing when system activity is
> low ?
>
> Maintenance
> ***********
> - Index compaction
> - Vacuum of various flavours

I had a couple thoughts about index compaction and vacuum in the
background:

Could one run a postgresql process in a lower priority process and
perform lazy vacuums without affecting performance all that much?

A live index compaction can be done by indexing the table with a
temporary name rename the old index, rename the new index to the old
name, and drop the old index.