From: | Dimitri <dimitrik(dot)fr(at)gmail(dot)com> |
---|---|
To: | "Rainer Bauer" <usenet(at)munnin(dot)com> |
Cc: | pgsql-performance(at)postgresql(dot)org |
Subject: | Re: Data transfer very slow when connected via DSL |
Date: | 2007-06-21 22:38:40 |
Message-ID: | 5482c80a0706211538ka531c18gcf681cd5a68066b2@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
Let's stay optimist - at least now you know the main source of your problem! :))
Let's see now with CURSOR...
Firstly try this:
munnin=>\timing
munnin=>\set FETCH_COUNT 1;
munnin=>select * from "tblItem";
what's the time you see here? (I think your application is working in
this manner)
Now, change the FETCH_COUNT to 10, then 50, then 100 - your query
execution time should be better (at least I hope so :))
And if it's better - you simply need to modify your FETCH clause with
adapted "FORWARD #" value (the best example is psql source code
itself, you may find ExecQueryUsingCursor function implementation
(file common.c))...
Rgds,
-Dimitri
On 6/22/07, Rainer Bauer <usenet(at)munnin(dot)com> wrote:
> Hello Dimitri,
>
> >but did you try to execute your query directly from 'psql' ?...
>
> munnin=>\timing
> munnin=>select * from "tblItem";
> <data snipped>
> (50 rows)
> Time: 391,000 ms
>
> >Why I'm asking: seems to me your case is probably just network latency
> >dependent, and what I noticed during last benchmarks with PostgreSQL
> >the SELECT query become very traffic hungry if you are using CURSOR.
> >Program 'psql' is implemented to not use CURSOR by default, so it'll
> >be easy to check if you're meeting this issue or not just by executing
> >your query remotely from 'psql'...
>
> Yes, see also my other post.
>
> Unfortunatelly this means that using my program to connect via DSL to the
> Postgres database is not possible.
>
> Rainer
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Have you searched our list archives?
>
> http://archives.postgresql.org
>
From | Date | Subject | |
---|---|---|---|
Next Message | Scott Marlowe | 2007-06-21 23:10:32 | Re: Performance query about large tables, lots of concurrent access |
Previous Message | Scott Marlowe | 2007-06-21 22:29:15 | Re: Hardware suggestions |