Postgresql Logger Process - postgresql

Question

I'm trying to determine if Postgres 9.3 still has a logger process. It isn't referenced anywhere in the "PostgreSQL 9.3.4 Documentation". And I can't find it in my cluster's process list (see below). Also, does anyone know of a good general overview the memory structures in 9.3?
postgres 21397 1 0 20:51 pts/1 00:00:00 /opt/PostgreSQL/9.3/bin/postgres
postgres 21399 21397 0 20:51 ? 00:00:00 postgres: checkpointer process
postgres 21400 21397 0 20:51 ? 00:00:00 postgres: writer process
postgres 21401 21397 0 20:51 ? 00:00:00 postgres: wal writer process
postgres 21402 21397 0 20:51 ? 00:00:00 postgres: autovacuum launcher process
postgres 21403 21397 0 20:51 ? 00:00:00 postgres: archiver process last was 0001000004000092
postgres 21404 21397 0 20:51 ? 00:00:00 postgres: stats collector process
Thanks
Jim

Answer 1

Postgres has a logging collector process which is controlled through a config parameter,
logging_collector.
So in your postgresql.conf file, you would make sure this is set:
logging_collector = on
The blurb on this param from the postgres doc:
This parameter enables the logging collector, which is a background
process that captures log messages sent to stderr and redirects them
into log files. This approach is often more useful than logging to
syslog, since some types of messages might not appear in syslog
output. (One common example is dynamic-linker failure messages;
another is error messages produced by scripts such as
archive_command.) This parameter can only be set at server start.
It will show up in the process list with the following description:
postgres: logger process
For more info: http://www.postgresql.org/docs/current/static/runtime-config-logging.html
Regarding the memory structures, I'm not sure offhand, but would recommend you post that as a separate question.