Question

I just discovered a bizarre behavior exhibited by MongoDB.

很显然,任何“系统”的收集名称都不正确。

To make matters worse, it won t even tell you anything is wrong!

这实际上更是一个好奇的问题,但没有人会想为什么会发生? 它是否记载了什么地方?

我的假设是,它利用“系统.*”收集来储存内部物品(如指数),并不想让你与他们交谈,但这似乎与我正确的行为一样。

Answer 1

You are correct "system.*" is a reserved collection namespace used by MongoDB in each DB.

它用于储存指数和用户等。

SQL 服务器也有许多这样的表格,我并不认为它们警告你不要使用这些表格:。

但是,你总是可以提出这种功能的请求:。

你们可以看看他们,......

<代码>>显示采集

和你看一看......

http://www.un.org。

<编码>系统>用户

因此,你可以看到你的指数:

> db.system.indexes.find()

摘自MongoDB :

The .system.* namespaces in MongoDB are special and contain database system information. System collections include:

system.namespaces lists all namespaces.

system.indexes lists all indexes.

Additional namespace / index metadata exists in the database.ns files, and is opaque.

system.profile stores database profiling information.

system.users lists users who may access the database.

local.sources stores replica slave configuration data and state.

Information on the structure of a stored object is stored within the object itself. See BSON .

There are several restrictions on manipulation of objects in the system collections. Inserting in system.indexes adds an index, but otherwise that table is immutable (the special drop index command updates it for you). system.users is modifiable. system.profile is droppable.

http://docs.mongodb.org/manual/fer/system-collections/

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