postgresql – 如何从Postgres内部列出文件夹中的文件？

有没有办法列出文件夹中的文件？

就像是：

select * from pg_ls_dir('/home/christian')

我试过pg_ls_dir但是,per documentation：

Only files within the database cluster directory and the log_directory
can be accessed. Use a relative path for files in the cluster
directory,and a path matching the log_directory configuration setting
for log files. Use of these functions is restricted to superusers.

我需要列出postgres目录之外的文件夹中的文件,类似于copY的操作方式.

它通常对sql客户端没用.

无论如何,你需要实现它,这是像plperlu这样的脚本语言的典型用例.例：

CREATE FUNCTION nosecurity_ls(text) RETURNS setof text AS $$
  opendir(my $d,$_[0]) or die $!;
  while (my $f=readdir($d)) {
    return_next($f);
  }
  return undef; 
$$language plperlu;

除了限制之外,这相当于System Administration Functions中提到的pg_ls_dir(text)函数.

=> select * from nosecurity_ls('/var/lib/postgresql/9.1/main') as ls;

      ls      
-----------------
 pg_subtrans
 pg_serial
 pg_notify
 pg_clog
 pg_multixact
 ..
 base
 pg_twophase
 etc...