Re: Input and Output data traffic

I'm not with java code right now, but the python one is this:

def inserir(self, curso):
cursor = self.conn.cursor()
cursor.execute("""insert into Curso(area, carga_horaria, ementa,
nome)
values(%s, %s, %s, %s)""",
(curso.area, curso.carga_horaria, curso.ementa,
curso.nome))
cursor.close()
self.conn.commit()

- Simple insert, without returning.
- With a proxy between application and database i measured the quantity of
transfered data.
- Executed 1000 times.

Note: I tried to reuse the same cursor (instead of creating a new one every
time) and didn't get any significant change.

About server side cursors, I thought that it would only matter for select
statements. Wouldn't? Is it possible to implement this differently?

2011/5/11 Karsten Hilbert <Karsten(dot)Hilbert(at)gmx(dot)net>

> On Wed, May 11, 2011 at 08:18:40AM -0300, Israel Ben Guilherme Fonseca
> wrote:
>
> > LOL, sorry I wasn't explicit in my text. But i did the same test with
> > psycopg2 too. :P
>
> :-) That makes better sense now.
>
> > "For simple inserts/updates/deletes i got a difference of about 15%
> between
> > sent and received data."
>
> ...
>
> > If someone could say: "well, sent/received data should be significantly
> > different and there is something wrong there", or "no it's normal". That
> > would be helpful.
>
> It very much depends on the exact queries used:
>
> 1) INSERT INTO my_table (a, b) VALUES (1, 2);
>
> 2) INSERT INTO my_table (a, b) VALUES (1, 2) RETURNING a, b;
>
> I would expect a lot more data to be returned with 2) than
> with 1).
>
> (That difference in testing setup does not explain the
> differences between drivers, though, if one assumes you've
> been using the very same queries with each.)
>
> The other thing is that one driver may be using server-side
> cursors while another driver will use client-side cursors.
> The latter will transfer a lot more data.
>
> I think you'd have to be more specific about the exact
> testing methodology to get useful advice.
>
> Karsten
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