Re: "Not safe to send CSV data" message

Tom Lane wrote:
> So I went to investigate bug #5196: turned on log_destination = csvlog
> etc, and restarted the postmaster.  I got this on stderr:
>
> 2009-11-18 20:08:52.104 EST : : LOG:  loaded library "passwordcheck"
> Not safe to send CSV data
>
> The first line is a consequence of having still got
> shared_preload_libraries set from testing the new contrib/passwordcheck
> module.  However, what I'm on the warpath about right now is the second
> line.  That message is useless, not to mention not conformant to our
> style guidelines.  

(donning armor)

Possibly.

> And the fact that it comes out at all suggests that
> the csvlog startup logic is rather broken.  Comments?
>
>   

Not sure why you say that. This can only happen very early in the 
startup process before the postmaster has had a chance to finish setting 
up the syslogger process and dup the pipes. As soon as that happens 
redirection_done is set to true and this message is no longer possible.

My memory is fading a bit about this now, but ISTR we debated the logic 
some when I was working to get this committed around 2 1/2 years ago. 
It's quite possible we (or I) got it wrong, but I'm not sure what we 
should be doing if the logger isn't ready yet.

BTW, re that bug, I recently turned on CSV logging under 8.3 for a 
client running Suse 10.2 64bit, with fairly heavy usage. Here is the 
current state of the non-client processes:

postgres  7080  0.0  0.4 12913224 267216 ?     S    Oct28   2:58 
/usr/bin/postmaster -D /pg_database/pg_data1/pg
postgres  7087  0.1  0.0  99824 60696 ?        Ss   Oct28  30:32 
postgres: logger process                      
postgres  7092  0.0 16.3 12919564 10791472 ?   Ss   Oct28   7:41 
postgres: writer process                      
postgres  7093  0.0  0.0 12919256 10432 ?      Ss   Oct28   0:29 
postgres: wal writer process                  
postgres  7094  0.0  0.0 12920892 3544 ?       Ss   Oct28   0:00 
postgres: autovacuum launcher process         
postgres  7095  0.0  0.0  34396  1904 ?        Ss   Oct28   0:05 
postgres: archiver process   last was 0000000100000205000000A3
postgres  7096  0.0  0.0  36156  2916 ?        Ss   Oct28  10:26 
postgres: stats collector process  

So the logger there has been doing CSV logging for quite a while without 
memory ballooning.  (The writer process, on the other hand, has eaten up 
a boatload of memory, by the look of it)      

cheers

andrew