# 51.67. pg\_available\_extension\_versions

pg\_available\_extension\_versions 檢視圖列出可用於安裝的特定延伸功能版本。另請參閱 [pg\_extension](/internals/system-catalogs/pg_extension.md) 目錄，該目錄列出了目前已安裝的延伸功能。

#### **Table 51.68. `pg_available_extension_versions` Columns**

| Name          | Type     | Description                         |
| ------------- | -------- | ----------------------------------- |
| `name`        | `name`   | 延伸功能名稱                              |
| `version`     | `text`   | 版本名稱                                |
| `installed`   | `bool`   | 如果目前已安裝此延伸功能的此版本，則為 True            |
| `superuser`   | `bool`   | 如果僅允許超級使用者安裝此延伸功能，則為 True           |
| `relocatable` | `bool`   | 如果延伸功能可以接受重新定位到另一個綱要，則為 True        |
| `schema`      | `name`   | 延伸功能必須安裝到的綱要名稱，如果可部分或完全重新定位，則為 NULL |
| `requires`    | `name[]` | 必須預先安裝的延伸功能名稱，如果沒有則為 NULL           |
| `comment`     | `text`   | 延伸功能控制檔案中的註解文字內容                    |

pg\_available\_extension\_versions 檢視表是唯讀的。


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