Re: [PATCH] Log crashed backend's query (activity string)

Excerpts from Marti Raudsepp's message of mié sep 07 18:09:32 -0300 2011:
> On Wed, Sep 7, 2011 at 22:42, Alvaro Herrera <alvherre(at)commandprompt(dot)com> wrote:
> > A mishandled encoding conversion could be problematic, so that needs to
> > be carefully considered (perhaps just shut off unconditionally).
>
> Are you referring to log file encoding or something else? The log file
> is already potentially mixed-encoding, as different databases may have
> different encodings and backends just dump bytes to it in their
> current encoding.

I am referring to the fact that whatever the backend puts in shared
memory is going to be in its encoding setting, which may not necessarily
match the postmaster's. And if it doesn't, the postmaster might try to
convert it using settings not valid for the string, possibly leading to
crashes.

I remember we had bugs whereby an encoding conversion would fail,
leading to elog trying to report this problem, but this attempt would
also incur a conversion step, failing recursively until elog's stack got
full. I'm not saying this is impossible to solve, just something to
keep in mind.

--
Álvaro Herrera <alvherre(at)commandprompt(dot)com>
The PostgreSQL Company - Command Prompt, Inc.
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