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Re: Input and Output data traffic

From: Israel Ben Guilherme Fonseca <israel(dot)bgf(at)gmail(dot)com>
To: psycopg(at)postgresql(dot)org
Subject: Re: Input and Output data traffic
Date: 2011-05-11 16:56:08
Message-ID: BANLkTin-nfzw2dF3x3oeWefkg=dtAQ1kVQ@mail.gmail.com (view raw or flat)
Thread:
Lists: psycopg
With the log tips of Oswaldo, I saw that

SET TRANSACTION ISOLATION LEVEL READ COMMITTED

on every instruction as you said Danielle. JDBC dont have those and it use
parameters for the statements, psycopg do not (its embedded in the SQL). I
dont know if this could have some impact.

I used the recommended way to avoid SQL Injection by the way.

execute("insert into table(col) values(%s)", (10,))

--

Anyway, I wil try to get more careful look on this later(maybe not today,
but soon), and tell you guys what happened.

Thanks very much for all the support.



2011/5/11 Daniele Varrazzo <daniele(dot)varrazzo(at)gmail(dot)com>

> On Wed, May 11, 2011 at 3:38 PM, Israel Ben Guilherme Fonseca
> <israel(dot)bgf(at)gmail(dot)com> wrote:
>
> > I'm explicitly committing the insert instruction at every iteration, so I
> > don't think that's possible to cache all the inserts in one statement
> like
> > you did.
>
> In this case, it may be due to the "set isolation level" issued
> together with the "begin" by psycopg. Because you send a very short
> statement between BEGIN/COMMIT pair the code for the set could be a
> relevant part of the communication. The overhead would be less
> relevant with bigger commands per transaction of course.
>
> This is a point I just wanted to talk about on the ML: will try to
> write this evening/in the next few days.
>
> -- Daniele
>

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Subject: Re: Input and Output data traffic
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