centos 6.8 + postgresql 9.6 + adminpack

adminpack提供了一些支持函数，pgAdmin和其他管理工具会用这些函数来提供额外的功能，例如服务器日志文件的远程管理。
只有超级用户才能使用全部这些函数。

mondb=#  select * 
mondb-#    from pg_available_extensions
mondb-#   where 1=1
mondb-#     and name like '%adminpack%';
   name    | default_version | installed_version |                 comment                 
-----------+-----------------+-------------------+-----------------------------------------
 adminpack | 1.0             | 1.0               | administrative functions for PostgreSQL
(1 row)


mondb=# create extension adminpack;
CREATE EXTENSION

mondb=#  select *
mondb-#    from pg_extension 
mondb-#   where 1=1
mondb-#     and extname like '%adminpack%';
  extname  | extowner | extnamespace | extrelocatable | extversion | extconfig | extcondition 
-----------+----------+--------------+----------------+------------+-----------+--------------
 adminpack |       10 |           11 | f              | 1.0        |           | 
(1 row)

mondb=# select pp.proname,
mondb-#        pp.prosrc,
mondb-#        pp.probin
mondb-# from pg_proc pp
mondb-# where 1=1
mondb-# and pp.probin like '%adminpack%'
mondb-# ;
    proname     |     prosrc     |      probin       
----------------+----------------+-------------------
 pg_file_write  | pg_file_write  | $libdir/adminpack
 pg_file_rename | pg_file_rename | $libdir/adminpack
 pg_file_unlink | pg_file_unlink | $libdir/adminpack
 pg_logdir_ls   | pg_logdir_ls   | $libdir/adminpack
(4 rows)

$ cd /usr/pgsql-9.6/share/extension/
$ ls -l |grep -i admin
-rw-r--r-- 1 root root  1535 Aug 10 10:15 adminpack--1.0.sql
-rw-r--r-- 1 root root   176 Aug 10 10:15 adminpack.control

$ more adminpack--1.0.sql
/* contrib/adminpack/adminpack--1.0.sql */

-- complain if script is sourced in psql, rather than via CREATE EXTENSION
\echo Use "CREATE EXTENSION adminpack" to load this file. \quit

/* ***********************************************
 * Administrative functions for PostgreSQL
 * *********************************************** */

/* generic file access functions */

CREATE FUNCTION pg_catalog.pg_file_write(text, text, bool)
RETURNS bigint
AS 'MODULE_PATHNAME', 'pg_file_write'
LANGUAGE C VOLATILE STRICT;

CREATE FUNCTION pg_catalog.pg_file_rename(text, text, text)
RETURNS bool
AS 'MODULE_PATHNAME', 'pg_file_rename'
LANGUAGE C VOLATILE;

CREATE FUNCTION pg_catalog.pg_file_rename(text, text)
RETURNS bool
AS 'SELECT pg_catalog.pg_file_rename($1, $2, NULL::pg_catalog.text);'
LANGUAGE SQL VOLATILE STRICT;

CREATE FUNCTION pg_catalog.pg_file_unlink(text)
RETURNS bool
AS 'MODULE_PATHNAME', 'pg_file_unlink'
LANGUAGE C VOLATILE STRICT;

CREATE FUNCTION pg_catalog.pg_logdir_ls()
RETURNS setof record
AS 'MODULE_PATHNAME', 'pg_logdir_ls'
LANGUAGE C VOLATILE STRICT;


/* Renaming of existing backend functions for pgAdmin compatibility */

CREATE FUNCTION pg_catalog.pg_file_read(text, bigint, bigint)
RETURNS text
AS 'pg_read_file'
LANGUAGE INTERNAL VOLATILE STRICT;

CREATE FUNCTION pg_catalog.pg_file_length(text)
RETURNS bigint
AS 'SELECT size FROM pg_catalog.pg_stat_file($1)'
LANGUAGE SQL VOLATILE STRICT;

CREATE FUNCTION pg_catalog.pg_logfile_rotate()
RETURNS int4
AS 'pg_rotate_logfile'
LANGUAGE INTERNAL VOLATILE STRICT;