Re: Building multiple indexes concurrently

On Wednesday 17 March 2010 22:18:47 Hannu Krosing wrote:
> On Wed, 2010-03-17 at 16:49 -0400, Greg Smith wrote:
> > Alvaro Herrera wrote:
> > > Andres Freund escribió:
> > >> I find it way much easier to believe such issues exist on a tables in
> > >> constrast to indexes. The likelihood to get sequential accesses on an
> > >> index is small enough on a big table to make it unlikely to matter
> > >> much.
> > >
> > > Vacuum walks indexes sequentially, for one.
> >
> > That and index-based range scans were the main two use-cases I was
> > concerned would be degraded by interleaving index builds, compared with
> > doing them in succession.
>
> I guess that tweaking file systems to allocate in bigger chunks help
> here ? I know that xfs can be tuned in that regard, but how about other
> common file systems like ext3 ?
ext4 should do that now by allocating the space for the files only after some
time or uppon things like fsync (xfs does the same).
ext3 has, as far as I know, neither the ability to change allocation size nor
can do delayed allocation.

Andres