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- dbStats
dbStats¶
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Definition¶
-
dbStats
¶ The
dbStats
command returns storage statistics for a given database. The command takes the following syntax:The values of the options above do not affect the output of the command. The
scale
option allows you to specify how to scale byte values. For example, ascale
value of1024
will display the results in kilobytes rather than in bytes:Note
Because scaling rounds values to whole numbers, scaling may return unlikely or unexpected results.
The time required to run the command depends on the total size of the database. Because the command must touch all data files, the command may take several seconds to run.
In the
mongo
shell, thedb.stats()
function provides a wrapper arounddbStats
.
Output¶
-
dbStats.
db
¶ Contains the name of the database.
-
dbStats.
collections
¶ Contains a count of the number of collections in that database.
-
dbStats.
objects
¶ Contains a count of the number of objects (i.e. documents) in the database across all collections.
-
dbStats.
avgObjSize
¶ The average size of each document in bytes. This is the
dataSize
divided by the number of documents.
-
dbStats.
dataSize
¶ The total size in bytes of the data held in this database including the padding factor. The
scale
argument affects this value. ThedataSize
will not decrease when documents shrink, but will decrease when you remove documents.
-
dbStats.
storageSize
¶ The total amount of space in bytes allocated to collections in this database for document storage. The
scale
argument affects this value. ThestorageSize
does not decrease as you remove or shrink documents.
-
dbStats.
numExtents
¶ Contains a count of the number of extents in the database across all collections.
-
dbStats.
indexes
¶ Contains a count of the total number of indexes across all collections in the database.
-
dbStats.
indexSize
¶ The total size in bytes of all indexes created on this database. The
scale
arguments affects this value.
-
dbStats.
fileSize
¶ The total size in bytes of the data files that hold the database. This value includes preallocated space and the padding factor. The value of
fileSize
only reflects the size of the data files for the database and not the namespace file.The
scale
argument affects this value. Only present when using themmapv1
storage engine.
-
dbStats.
nsSizeMB
¶ The total size of the namespace files (i.e. that end with
.ns
) for this database. You cannot change the size of the namespace file after creating a database, but you can change the default size for all new namespace files with thensSize
runtime option.Only present when using the
mmapv1
storage engine.See also
The
nsSize
option, and Maximum Namespace File Size
-
dbStats.
dataFileVersion
¶ New in version 2.4.
Document that contains information about the on-disk format of the data files for the database. Only present when using the
mmapv1
storage engine.
-
dbStats.dataFileVersion.
major
¶ New in version 2.4.
The major version number for the on-disk format of the data files for the database. Only present when using the
mmapv1
storage engine.
-
dbStats.dataFileVersion.
minor
¶ New in version 2.4.
The minor version number for the on-disk format of the data files for the database. Only present when using the
mmapv1
storage engine.
-
dbStats.
extentFreeList
¶ New in version 3.0.0.
-
dbStats.extentFreeList.
num
¶ New in version 3.0.0.
Number of extents in the freelist. Only present when using the
mmapv1
storage engine.
-
dbStats.extentFreeList.
size
¶ New in version 3.0.0.
Total size of the extents on the freelist.
The
scale
argument affects this value. Only present when using themmapv1
storage engine.