db.stats()

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Description

Behavior
Example

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Description

db.stats(scale)

Returns statistics that reflect the use state of a single database.

The db.stats() method is a wrapper around the dbStats database command.

Parameters

The db.stats() method has the following optional parameter:

Parameter	Type	Description
scale	number	Optional. The scale factor for the various size data. The `scale` defaults to 1 to return size data in bytes. To display kilobytes rather than bytes, specify a `scale` value of `1024`. If you specify a non-integer scale factor, MongoDB uses the integer part of the specified factor. For example, if you specify a scale factor of `1023.999`, MongoDB uses `1023` as the scale factor. Starting in version 4.2, the output includes the `scaleFactor` used to scale the size values.

Output

The db.stats() method returns a document with statistics reflecting the database system's state. For example:

{
   "db" : "test",
   "collections" : 6,
   "views" : 0,
   "objects" : 400629,
   "avgObjSize" : 663.996695196803,
   "dataSize" : 266016332,
   "storageSize" : 179838976,
   "indexes" : 13,
   "indexSize" : 9940992,
   "totalSize" : 189779968,
   "scaleFactor" : 1,
   "fsUsedSize" : 126727540736,
   "fsTotalSize" : 499963174912,
   "ok" : 1
}

For an explanation of the output, see Output.

Behavior

Accuracy after Unexpected Shutdown

After an unclean shutdown of a mongod using the Wired Tiger storage engine, count and size statistics reported by db.stats() may be inaccurate.

The amount of drift depends on the number of insert, update, or delete operations performed between the last checkpoint and the unclean shutdown. Checkpoints usually occur every 60 seconds. However, mongod instances running with non-default --syncdelay settings may have more or less frequent checkpoints.

Run validate on each collection on the mongod to restore statistics after an unclean shutdown.

After an unclean shutdown:

validate updates the count statistic in the collStats output with the latest value.
Other statistics like the number of documents inserted or removed in the collStats output are estimates.

Replica Set Member State Restriction

Starting in MongoDB 4.4, to run on a replica set member, dbStats 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.

Example

The following example returns various size values in kilobytes:

db.stats(1024)

Note

The scale factor rounds values to whole numbers.

Back

db.shutdownServer()

db.version()