F.1. adminpack

adminpack 提供了許多支援性質的函數，pgAdmin 和其他管理工具可以用來提供其他功能，例如伺服器日誌檔案的遠程管理。預設情況下，僅超級使用者可以使用所有的這些函數，但使用 GRANT 指令可以允許其他使用者使用它們。

Table F.1 中列出的函數提供了對伺服器的主機上檔案的寫入功能。 （另請參見 Table 9.95 中提供唯讀的功能。）只能存取資料庫叢集目錄中的檔案，除非使用者是超級使用者或具有 pg_read_server_files 或 pg_write_server_files 個角色（視情況而定） ，而相對路徑及絕對路徑都是允許的。

Table F.1. adminpack Functions

Function Description
pg_catalog.pg_file_write ( filename text, data text, append boolean ) → bigint Writes, or appends to, a text file.
pg_catalog.pg_file_sync ( filename text ) → void Flushes a file or directory to disk.
pg_catalog.pg_file_rename ( oldname text, newname text [, archivename text ] ) → boolean Renames a file.
pg_catalog.pg_file_unlink ( filename text ) → boolean Removes a file.
pg_catalog.pg_logdir_ls () → setof record Lists the log files in the log_directory directory.

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.