# 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](#table-f-1-adminpack-functions) 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](https://docs.postgresql.tw/14/the-sql-language/functions-and-operators/system-administration#table-9-95-generic-file-access-functions) 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**

| <p>Function</p><p>Description</p>                                                                                                                                                                                                                                     |
| --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| <p><code>pg\_catalog.pg\_file\_write</code> ( <em><code>filename</code></em> <code>text</code>, <em><code>data</code></em> <code>text</code>, <em><code>append</code></em> <code>boolean</code> ) → <code>bigint</code></p><p>Writes, or appends to, a text file.</p> |
| <p><code>pg\_catalog.pg\_file\_sync</code> ( <em><code>filename</code></em> <code>text</code> ) → <code>void</code></p><p>Flushes a file or directory to disk.</p>                                                                                                    |
| <p><code>pg\_catalog.pg\_file\_rename</code> ( <em><code>oldname</code></em> <code>text</code>, <em><code>newname</code></em> <code>text</code> \[, <em><code>archivename</code></em> <code>text</code> ] ) → <code>boolean</code></p><p>Renames a file.</p>          |
| <p><code>pg\_catalog.pg\_file\_unlink</code> ( <em><code>filename</code></em> <code>text</code> ) → <code>boolean</code></p><p>Removes a file.</p>                                                                                                                    |
| <p><code>pg\_catalog.pg\_logdir\_ls</code> () → <code>setof record</code></p><p>Lists the log files in the <code>log\_directory</code> directory.</p>                                                                                                                 |

`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](https://www.postgresql.org/docs/13/runtime-config-error-handling.html#GUC-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](https://www.postgresql.org/docs/13/runtime-config-logging.html#GUC-LOG-DIRECTORY) directory. The [log\_filename](https://www.postgresql.org/docs/13/runtime-config-logging.html#GUC-LOG-FILENAME) parameter must have its default setting (`postgresql-%Y-%m-%d_%H%M%S.log`) to use this function.