Re: Extremely slow queries in pgAdminIII

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От Asger Petersen
Тема Re: Extremely slow queries in pgAdminIII
Дата
Msg-id 6A0257B028DA47499B5A843683051A36068D38@server01.jo-informatik.local
обсуждение исходный текст
Ответ на Extremely slow queries in pgAdminIII  ("Asger Petersen" <asger@jo-informatik.dk>)
Ответы Re: Extremely slow queries in pgAdminIII  (Andreas Pflug <pgadmin@pse-consulting.de>)
Список pgadmin-support
Hi again

Now i uninstalled 8.0rc2 and installed a 8.0.1 on the server. I also
copied the libpq.dll (v. 8.0.1.5031) to the slow client and did the
simple test again. Same result :-( I'm sure that the slow client uses
the new libpq, as this is the only version of the file on the machine.
The client on the server is still slow and the fast client is still
fast.

When using pgAdmin to execute the 'SELECT * FROM table' on the slow
client this happens:
The network traffic is constant at 0.3 Mbit (connection is 1GBit) for
approx 410 secs. Then I'm asked whether i really want to fetch 37000
rows. If I accept it takes approx 19 secs to retrieve the rows.

On the fast client the same query results in 10Mbits of network traffic
(connection is 100 MBit) and the timings are approx 10000 ms + 19000 ms.

So this could indicate network problems. However when using pgAdminIII
or psql on the server itself there is no network traffic and the query
takes 160 secs to complete. There is no cpu use during the 160 seconds.

In all cases limiting the query to a small number of rows (~10) will
make the query complete in <1 sec.

I'm not sure how to check client side encoding.

The server is a test setup to convince the boss about PostgreSQL. I have
now been allowed to install it on a production server, so hopefully the
problem will be solved by the switch of machines. I still think it
should be investigated why a clean install on a server that is known to
work with other software just doesn't work. If you think it could be of
use to you i will of course do the necessary testing of the problematic
server.

Regards
Asger

> It changed in XPSP1 and Win2003 server.
> >> Trying to dig deeper into this, I have used psql on the
> database host
> >> and on the fast client. On the host my query took forever
> whereas it
> >> finished in 10 secs on the fast client. So to me it seems
> pgAdmin is
> >> not really the problem here, but now I have no idea where to
> >look next :-(
> >
> >No - it's beginning to sound more like a network issue. Anything odd
> >about the network config on any of those machines, or the
> switches they
> >connect to? Firewalls, that sort of thing? Mind you, it's
> odd that it's
> >slow running the client on the server as well....
> >
> >Magnus - this is the case I mentioned yesterday. There is no obvious
> >relationship between libpq versions and slow/fast machines.
> One of the
> >slow machines is the server itself, and it seems that psql
> is affected
> >as well. Any ideas?
>
> Not offhand.
> Is it the connection that is slow, or the query runtime?
> Any dealings with client side encodings that are different?
> Is plain TCP flowing fast between these machines? Other kind of
> networking stuff?
>
>
> //Magnus
>


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