Re: [Postgres-xc-developers] [Postgres-xc-general] IO PGXC

[Nikhil S. <ni...@st...>]

>
> We are running metrics on the system now, we loaded some data recently, and
> continuing to do so now. If Hint bits are the case, what steps can I take to
> relieve some of this IO?
>

This is internal IO which will settle down if you are not loading into
the same table again immediately. A lumpsum count(1) call (after a
recent data load) will touch all pages immediately, so try to avoid
that and amortize the IO over multiple specific select calls.

HTH,
Nikhils


>
>
> From: Mason Sharp [mailto:ma...@st...]
> Sent: Friday, March 01, 2013 2:29 PM
> To: Arni Sumarlidason
> Cc: pos...@li...; Postgres-XC Developers
> (pos...@li...)
> Subject: Re: [Postgres-xc-general] IO PGXC
>
>
>
>
> Sent from my IPhone
>
>
> On Mar 1, 2013, at 4:13 PM, Arni Sumarlidason <Arn...@md...>
> wrote:
>
> Users,
>
>
>
> I have 20 nodes sitting on a disk arrays, with multiple LUNs. when I issue
> queries – `select count(1) from table` for example, I am experiencing heavy
> writes and heavy reads. I expected the reads but not the writes and it has
> really thrown a wrench in the caching. My first assumption would be the log
> files, do you have any other ideas what could be causing all these writes
> with a select?
>
>
>
> It could be vacuum. Also, did you just load data? Hint bits get updated,
> dirtying pages and causing them to be written.
>
>
>
>
>
> Arni Sumarlidason | Software Engineer, Information Technology
>
> MDA | 820 West Diamond Ave | Gaithersburg, MD | USA
>
> O: 240-833-8200 D: 240-833-8318 M: 256-393-2803
>
> arn...@md...| http://www.mdaus.com
>
>
>
> ------------------------------------------------------------------------------
> Everyone hates slow websites. So do we.
> Make your web apps faster with AppDynamics
> Download AppDynamics Lite for free today:
> http://p.sf.net/sfu/appdyn_d2d_feb
>
> _______________________________________________
> Postgres-xc-general mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-general



-- 
StormDB - http://www.stormdb.com
The Database Cloud
Postgres-XC Support and Service