adminpack provides a number of support functions which
pgAdmin and other administration and management tools can
use to provide additional functionality, such as remote management
of server log files.
Use of all these functions is only allowed to database superusers by default, but may be
allowed to other users by using the GRANT command.
The functions shown in Table F.1 provide
write access to files on the machine hosting the server. (See also the
functions in Table 9.101, which
provide read-only access.)
Only files within the database cluster directory can be accessed, unless the
user is a superuser or given privileges of one of the
pg_read_server_files or
pg_write_server_files roles, as appropriate for the
function, but either a relative or absolute path is allowable.
Table F.1. adminpack Functions
Function Description |
|---|
Writes, or appends to, a text file. |
Flushes a file or directory to disk. |
Renames a file. |
Removes a file. |
Lists the log files in the |
pg_file_write writes the specified data into
the file named by filename. If append is
false, the file must not already exist. If append is true,
the file can already exist, and will be appended to if so.
Returns the number of bytes written.
pg_file_sync fsyncs the specified file or directory
named by filename. An error is thrown
on failure (e.g., the specified file is not present). Note that
data_sync_retry has no effect on this function,
and therefore a PANIC-level error will not be raised even on failure to
flush database files.
pg_file_rename renames a file. If archivename
is omitted or NULL, it simply renames oldname
to newname (which must not already exist).
If archivename is provided, it first
renames newname to archivename (which must
not already exist), and then renames oldname
to newname. In event of failure of the second rename step,
it will try to rename archivename back
to newname before reporting the error.
Returns true on success, false if the source file(s) are not present or
not writable; other cases throw errors.
pg_file_unlink removes the specified file.
Returns true on success, false if the specified file is not present
or the unlink() call fails; other cases throw errors.
pg_logdir_ls returns the start timestamps and path
names of all the log files in the log_directory
directory. The log_filename parameter must have its
default setting (postgresql-%Y-%m-%d_%H%M%S.log) to use this
function.