Server instrumentation

This post includes "dbsize backend integration" and "Server
instrumentation: pg_terminate_backend, pg_reload_conf"

Server instrumentation functions included:

pg_tablespace_size()
pg_database_size()
pg_relation_size()
pg_size_pretty()
well-known from contrib/dbsize, waiting in unapplied patches
http://candle.pha.pa.us/mhonarc/patches/msg00002.html

The rest is superuser only:

pg_terminate_backend()
exposing kill -SIGTERM <backendpid> to the client
pg_reload_conf()
SIGHUP to reload configuration files

pg_logfile_rotate()
Logfile rotation
pg_logdir_ls() and view pg_logdir_ls
lists all available log files in the log directory.

As posted in the initial version of the logger subprocess from July 2004.

pg_file_stat()
pg_file_length()
pg_file_read()
pg_file_write()
pg_file_unlink()
pg_file_rename()
pg_dir_ls()
generic file functions to access files in logdir and cluster dir.
These functions where implemented as initiated by Bruce, and discussed
intensively in
http://archives.postgresql.org/pgsql-patches/2004-07/msg00287.php

All functions are fully documented.
Additionally, documentation for pg_postmaster_start_time is included,
the code itself ist posted by Matthias Schmidt
http://candle.pha.pa.us/mhonarc/patches/msg00008.html

Regards,
Andreas