Mongodb database maximum amount of data that supports what

limit

MongoDB is usually applied to 64-bit operating system, 32-bit systems can only address 4GB of memory, meaning that the data set that contains metadata and reach 4GB storage, Mongodb can not store additional data, it is strongly recommended to use 32-bit system can test their Mongodb use, production using a 64-bit operating system.
The maximum document size helps to ensure that a single document will not use too much RAM or take up too much bandwidth during transmission. To store the document is larger than the maximum size, MongoDB provides GridFS API.
MongoDB support BSON document nesting level does not exceed 100.

Database naming restrictions

Because the database name in MongoDB is not case sensitive , so the database name is not only due to the case of the characters is different.
For MongoDB deployment running on Windows, database name can not contain any of the following characters:

/. "$*<>:|?

For MongoDB deployment running on Unix and Linux systems, database name can not contain any of the following characters:

/. "$
Database name can not contain null characters. The database name can not be empty, and must be less than 64 characters.

Limit the collection named
collection name should begin with an underscore or alphabetic character, and can not :

It included $.
Is an empty string (e.g. "").
It contains a null character.
To system.begin with the prefix. (Reserved for internal use)
the maximum length of the name space is a set of 120 bytes, including the database name, point ( .) collection name and a delimiter (i.e. <database>.<collection>)

Field naming restrictions

Field names can not contain nullcharacters.
Top field names can not be a dollar sign ( $beginning) characters.
Other cases, starting with MongoDB 3.6, allows storage server that contains point (ie .) and dollar sign (ie $) field names.
mognodb does not support duplicate field names, even if the program successfully inserted, no exception is thrown, the driver can lead to default remove duplicate values before insertion.

Namespaces

The maximum length of the collection name space is 120 bytes, including the database name, point ( .separators and collection name (i.e.) <database>.<collection>)
changed in version 3.0.

For the number of MMAPv1, the name space is limited namespace file size divided by 628, a 16 MB file name space can support approximately 24,000 namespaces. Each collection is a name and index space.
WiredTiger storage engine is not subject to this restriction.
This is why starting from version 4.2 in MongoDB4.2, delete MMAPv1 storage engine is not recommended for use reason.

Replica set

In Mongodb3.0 most members of the replica set supports up to 50, that is to say the replica set bigger support 50 nodes, each node replica set of data to support 32T, a copy of the data set for each instance recommended not to exceed 4T, the amount of data backup recovery time will be very long.

Storage Limits

We usually use the default slice chunk size is 64M, if we fragment key (key sheet) values the value is 512 bytes, the maximum fragment node supports 32768 is the maximum amount of support data 32768TB.
A key sheet size can not exceed 512 bytes.