db.collection.dataSize()

db.collection.dataSize()

Important

mongosh Method

This page documents a mongosh method. This is not the documentation for database commands or language-specific drivers, such as Node.js.

For the database command, see the size field returned by the collStats command.

For MongoDB API drivers, refer to the language-specific MongoDB driver documentation.

For the legacy mongo shell documentation, refer to the documentation for the corresponding MongoDB Server release:

• mongo shell v4.4

• mongo shell v4.2

Returns:	The size in bytes of the collection. Data compression does not affect this value.

Starting in MongoDB 4.4, to run on a replica set member, collStats operations require the member to be in PRIMARY or SECONDARY state. If the member is in another state, such as STARTUP2, the operation errors.

In previous versions, the operations also run when the member is in STARTUP2. The operations wait until the member transitioned to RECOVERING.