Re: localhost (windows) performance - Mailing list pgsql-general

On Tuesday 07 October 2008 08:54:31 am justin wrote:
> johnf wrote:
> > I have a friend I asked to load postgres 8.3 on his XP machine.  He then
> > tested a python script which accesses several tables and discovered that
> > it retrieves data very slowly.  It takes about 20 seconds to retrieve the
> > data - on localhost.  However, using a remote connection to a postgres
> > database (mine) over the internet and running the same python script it
> > takes only 12 seconds.  The difference of 8 seconds makes no sense - the
> > remote is completely on the other coast.
> >
> > I then thought it had something to do with the data -although the data
> > set is small.  I did a complete dump and restored on his machine and
> > again got the same results.  The machine has a recent motherboard with 2
> > gb of ram.  It does not appear to be swapping out ram.
> >
> >
> > Using my local XP (accessing the LINUX database on the LAN) runs the same
> > python script in just under 3 seconds (most of the time is in loading the
> > GUI).
> >
> > One other major difference is I'm running postgres8.2 on linux.
> >
> > Anybody, have a suggestion - I'm not a windows guru.  Or is this normal
> > for windows?
>
> Hardware related i'm betting.  The client is having to run the python the
> gui and postgresql on the same hard drive its getting IO bound
>
> What size is the data set  1 meg  20 megs or 100 megs.  I have seen small
> record counts but it was nothing but blobs in the table so the table was 5
> gigs.
>
> What is the hardware specs on the XP machine??  Can you post the Select
> statements???

SELECT pg_database.datname,
pg_size_pretty(pg_database_size(pg_database.datname)) AS size
FROM pg_database

reveals
"5801 kB"

Like I said very small.

All the statements are similar:
select * from arcust where ccustno = "some var"

No blobs - there are a couple of 'text' fields.

Total data retrieved is very small - just a few thousand bytes.

If haven't said - this is a test database that contains only small amounts of
data.

Looks like we have gotten a major improvement by changing the shared-buffers.





--
John Fabiani