Re: PostgreSQL - Debian - Processes: postgres: writer process, etc.

On 15/02/12 06:16, Bruce Momjian wrote:
> On Mon, Jan 30, 2012 at 11:05:10AM -0500, Tom Lane wrote:
>>>> What is weird to me is the "COMMAND" column as far as these four processes
>>>> are concerned.
>>>> In the "COMMAND "column I would expect a real command, not a description.
>>>> Can you explain?
>> We intentionally change the command string reported by ps for each
>> postmaster child process, so that you can tell the various processes
>> apart. If we did not, every postmaster child would show the exact
>> same command string as the postmaster itself was launched with.
>> (To get an idea of how useless that is, try looking at "top" sometime
>> --- on most systems I've worked with, it ignores the changed command
>> strings, so you can't tell what's what.)
> I belive the 'c' command in modern versions of top toggles display of
> the current command string.
>
Yes, pressing 'c' when top is running gives a fuller description of the
process command string, had done in Fedora for longer than I can
remember. So I would be surprised if any Linux distribution had not had
it for several years.

you can also try
ps aux | grep postgres
at the command line prompt

$ ps aux | grep postgres
postgres 1777 0.0 0.8 2352592 66692 ? S 11:21 0:01
/usr/bin/postgres -D /var/lib/pgsql/data -p 5432
postgres 2979 0.0 0.0 181024 952 ? Ss 11:21 0:00
postgres: logger process
postgres 2989 0.0 0.1 2353620 14532 ? Ss 11:21 0:00
postgres: writer process
postgres 2990 0.0 0.0 2353620 1092 ? Ss 11:21 0:00
postgres: wal writer process
postgres 2991 0.0 0.0 2354356 2380 ? Ss 11:21 0:00
postgres: autovacuum launcher process
postgres 2992 0.0 0.0 183120 1160 ? Ss 11:21 0:00
postgres: stats collector process
gavin 5450 0.0 0.0 109248 848 pts/13 S+ 11:45 0:00 grep
--color=auto postgres
$