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Definition![](/docs/v5.3/assets/link.svg)
dataSize
The
dataSize
command returns the size in bytes for the specified data:{ dataSize: <string>, keyPattern: <document>, min: <document>, max: <document>, estimate: <boolean> } The command takes the following fields:
FieldTypeDescriptiondataSize
stringThe name of the target collection.keyPattern
documentOptional. The collection's key pattern to examine.
The collection must have an index with the corresponding pattern. Otherwise
dataSize
returns an error message.min
documentOptional. The lower bound of the key range to be examined.max
documentOptional. The upper bound of the key range to be examined.estimate
booleanOptional. When
true
,dataSize
estimates the data size by assuming that all documents in the specified range are uniformly sized as per the collection's average object size. The collection's average object size is obtained from theavgObjSize
field in the output of thecollStats
command.Defaults to false.
Example![](/docs/v5.3/assets/link.svg)
The following operation runs the dataSize
command on the
database.collection
collection, specifying a key pattern of {field: 1}
with the lower bound of the range of keys to be examined being {field: 10}
and the upper bound of the key to be examined being {field: 100}
.
db.runCommand({ dataSize: "database.collection", keyPattern: { field: 1 }, min: { field: 10 }, max: { field: 100 } })
This returns a document with the size in bytes for all matching
documents. Replace database.collection
with the database and
collection from your deployment.
The amount of time required to return dataSize
depends on the
amount of data in the collection.