Subject: Re: Building multiple indexes concurrently
From: Hannu Krosing <hannu@2ndquadrant.com>
To: Justin Pitts <justinpitts@gmail.com>
Cc: Greg Smith <greg@2ndquadrant.com>,
	Alvaro Herrera <alvherre@commandprompt.com>,
	Andres Freund <andres@anarazel.de>, pgsql-performance@postgresql.org,
	Rob Wultsch <wultsch@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
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Date: Thu, 18 Mar 2010 23:20:35 +0200
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On Thu, 2010-03-18 at 16:12 -0400, Justin Pitts wrote:
> It seems to me that a separate partition / tablespace would be a much simpler approach.

Do you mean a separate partition/ tablespace for _each_ index built
concurrently ?

> On Mar 17, 2010, at 5:18 PM, 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 ?
> > 
> > - 
> > Hannu Krosing   http://www.2ndQuadrant.com
> > PostgreSQL Scalability and Availability 
> >   Services, Consulting and Training
> > 
> > 
> > 
> > -- 
> > Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
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> 


-- 
Hannu Krosing   http://www.2ndQuadrant.com
PostgreSQL Scalability and Availability 
   Services, Consulting and Training