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 the superuser by default but may be allowed to other users by using the
The functions shown in Table F.1 provide write access to files on the machine hosting the server. (See also the functions in Table 9.95, which provide read-only access.) Only files within the database cluster directory can be accessed, unless the user is a superuser or given 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.
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
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
newname (which must not already exist). If
archivename is provided, it first renames
archivename (which must not already exist), and then renames
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_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.