# MongoDB系统集合

## Synopsis 概要

MongoDB stores system information in collections that use the `<database>.system.*` [namespace](https://docs.mongodb.com/manual/reference/glossary/#std-term-namespace), which MongoDB reserves for internal use. Do not create collections that begin with `system`.

MongoDB also stores some additional instance-local metadata in the [local database](https://docs.mongodb.com/manual/reference/local-database/), specifically for replication purposes and in the [config database](https://docs.mongodb.com/manual/reference/config-database/) for [sessions information](https://docs.mongodb.com/manual/core/read-isolation-consistency-recency/#std-label-sessions).

MongoDB将系统信息存储在使用`<database>.system.*`[命名空间](https://docs.mongodb.com/manual/reference/glossary/#std-term-namespace)的集合中，这些集合是MongoDB保留供内部使用的。用户请不要创建以`system`开头的集合。

MongoDB还将一些额外的本地元数据存储在[`local`数据库](https://docs.mongodb.com/manual/reference/local-database/)中，专门用于主从复制；并在[`config`数据库](https://docs.mongodb.com/manual/reference/config-database/)中存储[会话信息](https://docs.mongodb.com/manual/core/read-isolation-consistency-recency/#std-label-sessions)。

## Collections 集合

System collections include these collections stored in the `admin` database:

* `admin.system.roles`

  The [`admin.system.roles`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data-admin.system.roles) collection stores custom roles that administrators create and assign to users to provide access to specific resources.
* `admin.system.users`

  The [`admin.system.users`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data-admin.system.users) collection stores the user's authentication credentials as well as any roles assigned to the user. Users may define authorization roles in the [`admin.system.roles`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data-admin.system.roles) collection.
* `admin.system.version`

  The [`admin.system.version`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data-admin.system.version) collection stores metadata to suport internal operations. Do not modify this collection unless specifically instructed to in this documentation or by a MongoDB support engineer.

系统集合包括存储在`admin`数据库中的以下集合：

* **`admin.system.roles`**

  [`admin.system.roles`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data-admin.system.roles)集合存储管理员创建并分配给用户的自定义角色，以提供对特定资源的访问。
* **`admin.system.users`**

  [`admin.system.users`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data-admin.system.users)集合存储用户的身份验证凭据以及分配给该用户的所有角色。用户可以在 [`admin.system.roles`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data-admin.system.roles)集合中定义授权角色。
* **`admin.system.version`**

  [`admin.system.version`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data-admin.system.version)集合存储元数据以支持内部操作。除非本文档或MongoDB支持工程师明确指示，否则请勿修改此集合。

System collections include these collections stored in the `config` database:

* **`config.system.indexBuilds`**

  *New in version 4.4*.

  The [`indexBuilds`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data-config.system.indexBuilds) collection stores information related to in-progress index builds.

系统集合包括存储在`config`数据库中的以下集合：

* **`config.system.indexBuilds`**

  *4.4版本新引入*

  `indexBuilds`集合存储了与正在进行的索引创建有关的信息。

System collections also include these collections stored directly in each database:

* **`<database>.system.namespaces`**

  > **NOTE**
  >
  > **Removed in 4.2**
  >
  > Starting in MongoDB 4.2, `<database>.system.namespaces` has been removed (access to the collection has been deprecated since 3.0). To list the collections in a database, use the [`listCollections`](https://docs.mongodb.com/manual/reference/command/listCollections/#mongodb-dbcommand-dbcmd.listCollections) command instead.
* **`<database>.system.indexes`**

  > **NOTE**
  >
  > **Removed in 4.2**
  >
  > Starting in MongoDB 4.2, `<database>.system.indexes` has been removed (access to the collection has been deprecated since 3.0). To list the indexes, use the [`listIndexes`](https://docs.mongodb.com/manual/reference/command/listIndexes/#mongodb-dbcommand-dbcmd.listIndexes) command instead.
* **`<database>.system.profile`**

  The [`.system.profile`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data--database-.system.profile) collection stores database profiling information. For information on profiling, see [Database Profiling](https://docs.mongodb.com/manual/administration/analyzing-mongodb-performance/#std-label-database-profiling).
* **`<database>.system.js`**

  The [`.system.js`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data--database-.system.js) collection holds special JavaScript code for use in [server side JavaScript](https://docs.mongodb.com/manual/core/server-side-javascript/). See [Store a JavaScript Function on the Server](https://docs.mongodb.com/manual/tutorial/store-javascript-function-on-server/) for more information.
* **`<database>.system.views`**

  The [`<database>.system.views`](https://docs.mongodb.com/manual/reference/system-collections/#mongodb-data--database-.system.views) collection contains information about each [view](https://docs.mongodb.com/manual/core/views/) in the database.

系统集合还包括以下直接存储在每个数据库中的集合：

* **`<database>.system.namespaces`**

  > **注意**
  >
  > **4.2版本中被移除**
  >
  > 从MongoDB 4.2开始，`<database>.system.namespaces`已被删除（从3.0开始不推荐使用该集合）。要列出数据库中的集合，请改用[`listCollections`](https://docs.mongodb.com/manual/reference/command/listCollections/#mongodb-dbcommand-dbcmd.listCollections)命令。
* **`<database>.system.indexes`**

  > **注意**
  >
  > **4.2版本中被移除**
  >
  > 从MongoDB 4.2开始，`<database>.system.indexes`已被删除（从3.0开始不推荐使用该集合）。要列出数据库中的集合，请改用[`listIndexes`](https://docs.mongodb.com/manual/reference/command/listIndexes/#mongodb-dbcommand-dbcmd.listIndexes)命令。
* **`<database>.system.profile`**

  `<database>.system.profile`集合存储数据库分析信息。有关分析的信息，请参见[数据库分析](https://docs.mongodb.com/manual/administration/analyzing-mongodb-performance/#std-label-database-profiling)。
* **`<database>.system.js`**

  `<database>.system.js`集合包含用于[服务器端JavaScript](https://docs.mongodb.com/manual/core/server-side-javascript/)的特殊JavaScript代码。有关更多信息，请参见在[服务器上存储JavaScript函数](https://docs.mongodb.com/manual/tutorial/store-javascript-function-on-server/)。
* **`<database>.system.views`**

  `<database>.system.views`集合包含有关数据库中每个[视图](https://docs.mongodb.com/manual/core/views/)的信息。

译者：phoenix

时间： 2021.04.26

原文： <https://docs.mongodb.com/manual/reference/system-collections/>

版本： 4.4


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.mongoing.com/can-kao/sytem-collections.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.