Date: Wed, 3 Feb 2021 11:02:18 -0300
From: 'Alvaro Herrera' <alvherre@alvh.no-ip.org>
To: "tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com>
Cc: "iwata.aya@fujitsu.com" <iwata.aya@fujitsu.com>,
	"k.jamison@fujitsu.com" <k.jamison@fujitsu.com>,
	"'pgsql-hackers@lists.postgresql.org'" <pgsql-hackers@lists.postgresql.org>
Subject: Re: libpq debug log
Message-ID: <20210203140218.GA25720@alvherre.pgsql>
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On 2021-Feb-03, tsunakawa.takay@fujitsu.com wrote:

> From: 'Alvaro Herrera' <alvherre@alvh.no-ip.org>
> > > +		conn->fe_msg->num_fields != DEF_FE_MSGFIELDS)
> 
> > The rationale for that second condition is this: if the memory allocated
> > is the initial size, we don't free memory, because it would just be
> > allocated of the same size next time, and that size is not very big, so
> > it's not a big deal if we just let it be, so that it is reused if we
> > call PQtrace() again later.  However, if the allocated size is larger
> > than default, then it is possible that some previous tracing run has
> > enlarged the trace struct to a very large amount of memory, and we don't
> > want to leave that in place.
> 
> Ah, understood.  In that case, num_fields should be max_fields.

Oh, of course.


-- 
Álvaro Herrera                            39°49'30"S 73°17'W
"Just treat us the way you want to be treated + some extra allowance
 for ignorance."                                    (Michael Brusser)