From: Michael Fuhr <mike@fuhr.org>
To: Rodrigo Madera <rodrigo.madera@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Inefficient escape codes.
Date: Tue, 18 Oct 2005 14:47:27 -0600
Message-ID: <20051018204727.GA29110@winnie.fuhr.org> (raw)
In-Reply-To: <3cf983d0510181209v3070a81dw9b21d4d09cbb5022@mail.gmail.com>
References: <3cf983d0510181107sb060171je702da5fe0c29252@mail.gmail.com>
<20051018190324.GA92715@winnie.fuhr.org>
<3cf983d0510181209v3070a81dw9b21d4d09cbb5022@mail.gmail.com>
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On Tue, Oct 18, 2005 at 07:09:08PM +0000, Rodrigo Madera wrote:
> > What language and API are you using?
>
> I'm using libpqxx. A nice STL-style library for C++ (I am 101% C++).
I've only dabbled with libpqxx; I don't know if or how you can make
it send data in binary instead of text. See the documentation or
ask in a mailing list like libpqxx-general or pgsql-interfaces.
> > Binary transfer sends data in binary, not by automatically converting
> > to and from text.
>
> Uh, I'm sorry I didn't get that... If I send: insert into foo
> values('\\001\\002') will libpq send 0x01, 0x02 or "\\\\001\\\\002"??
If you do it that way libpq will send the string as text with escape
sequences; you can use a sniffer like tcpdump or ethereal to see this
for yourself. To send the data in binary you'd call PQexecParams()
with a query like "INSERT INTO foo VALUES ($1)". The $1 is a
placeholder; the other arguments to PQexecParams() provide the data
itself, the data type and length, and specify whether the data is in
text format or binary. See the libpq documentation for details.
--
Michael Fuhr
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To: pgsql-performance@postgresql.org
Cc: mike@fuhr.org, rodrigo.madera@gmail.com
Subject: Re: Inefficient escape codes.
In-Reply-To: <20051018204727.GA29110@winnie.fuhr.org>
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