Re: Copy to Csv file extremely slow

On Thu, May 30, 2013 at 12:48 PM, Jalisson Mello
<jalissonmeneses(at)hotmail(dot)com> wrote:
> Hi, I´m using the copy command to generate a csv file, but the generation
> its extremely slow in a production server. In our test's server this copy
> takes 20 minutes but in a production server this takes 2 days.
>
> The database that i used to the tests is a copy of the production database.
> The machines are totaly differents. Test Server is a simple Intel core 2
> duo 2.8 ghz with 8 GB Ram and Production Server has 2 xeon 2.8 ghz with 24
> GB RAM.
>
> Before the tests we ran vacuum and closed all another connections.
> The query takes 19 minutes and file generation less than 1 minute to create
> a file with 473 MB in the tests server. In Production server the query runs
> in the same 19 minutes, but file generation 2 days.
>
> I'm running postgresql 9.0 on CentOS 6.3 on both machines.
>
> Any idea about this big difference.
>
> Thanks , and sorry by my english.

have you ruled out o/s problems? what's iowait during this time? is
database writing to local storage?

merlin