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Database Commands

Database Commands¶

User Commands
Database Operations
Internal Commands
Testing Commands

All command documentation lined below describes the commands and available parameters, provides a document template or prototype for each command. Some command documentation also includes the relevant mongo.

User Commands¶

Aggregation Commands¶

Name	Description
`aggregate`	Performs aggregation tasks such as group using the aggregation framework.
`count`	Counts the number of documents in a collection.
`distinct`	Displays the distinct values found for a specified key in a collection.
`group`	Groups documents in a collection by the specified key and performs simple aggregation.
`mapReduce`	Performs map-reduce aggregation for large data sets.

Geospatial Commands¶

Name	Description
`geoNear`	Performs a geospatial query that returns the 100 documents closest to a given point.
`geoSearch`	Performs a geospatial query that uses MongoDB’s haystack index functionality.
`geoWalk`	An internal command to support geospatial queries.

Query and Write Operation Commands¶

Name	Description
`eval`	Runs a JavaScript function on the database server.
`findAndModify`	Returns and modifies a single document.
`getLastError`	Returns the success status of the last operation.
`getPrevError`	Returns status document containing all errors since the last `resetError` command.
`resetError`	Resets the last error status.
`text`	Performs a text search.

Database Operations¶

Replication Commands¶

Name	Description
`applyOps`	Internal command that applies oplog entries to the current data set.
`getoptime`	Internal command to support replication, returns the optime.
`isMaster`	Displays information about this member’s role in the replica set, including whether it is the master.
`replSetFreeze`	Prevents the current member from seeking election as primary for a period of time.
`replSetGetStatus`	Returns a document that reports on the status of the replica set.
`replSetInitiate`	Initializes a new replica set.
`replSetMaintenance`	Enables or disables a maintenance mode, which puts a secondary node in a `RECOVERING` state.
`replSetReconfig`	Applies a new configuration to an existing replica set.
`replSetStepDown`	Forces the current primary to step down and become a secondary, forcing an election.
`replSetSyncFrom`	Explicitly override the default logic for selecting a member to replicate from.
`resync`	Forces a `mongod` to re-synchronize from the master. For master-slave replication only.

See also

“Replica Set Fundamental Concepts” for more information regarding replication.

Sharding Commands¶

Name	Description
`addShard`	Adds a shard to a sharded cluster.
`checkShardingIndex`	Internal command that validates index on shard key.
`enableSharding`	Enables sharding on a specific database.
`flushRouterConfig`	Forces an update to the cluster metadata cached by a `mongos`.
`getShardMap`	Internal command that reports on the state of a sharded cluster.
`getShardVersion`	Internal command that returns the config server version.
`isdbgrid`	Verifies that a process is a `mongos`.
`listShards`	Returns a list of configured shards.
`medianKey`	Deprecated internal command. See `splitVector`.
`moveChunk`	Internal command that migrates chunks between shards.
`movePrimary`	Reassigns the primary shard when removing a shard from a sharded cluster.
`removeShard`	Starts the process of removing a shard from a sharded cluster.
`setShardVersion`	Internal command to sets the config server version.
`shardCollection`	Enables the sharding functionality for a collection, allowing the collection to be sharded.
`shardingState`	Reports whether the `mongod` is a member of a sharded cluster.
`splitChunk`	Internal command to split chunk. Instead use the methods `sh.splitFind()` and `sh.splitAt()`.
`splitVector`	Internal command that determines split points.
`split`	Creates a new chunk.
`unsetSharding`	Internal command that affects connections between instances in a MongoDB deployment.

See also

Sharding for more information about MongoDB’s sharding functionality.

Instance Administration Commands¶

Name	Description
`clean`	Internal namespace administration command.
`cloneCollectionAsCapped`	Copies a non-capped collection as a new capped collection.
`cloneCollection`	Copies a collection from a remote host to the current host.
`clone`	Copies a database from a remote host to the current host.
`closeAllDatabases`	Internal command that invalidates all cursors and closes open database files.
`collMod`	Add flags to collection to modify the behavior of MongoDB.
`compact`	Defragments a collection and rebuilds the indexes.
`connPoolSync`	Internal command to flush connection pool.
`convertToCapped`	Converts a non-capped collection to a capped collection.
`copydb`	Copies a database from a remote host to the current host.
`create`	Creates a collection and sets collection parameters.
`dropDatabase`	Removes the current database.
`dropIndexes`	Removes indexes from a collection.
`drop`	Removes the specified collection from the database.
`filemd5`	Returns the md5 hash for files stored using GridFS.
`fsync`	Flushes pending writes to the storage layer and locks the database to allow backups.
`getParameter`	Retrieves configuration options.
`logRotate`	Rotates the MongoDB logs to prevent a single file from taking too much space.
`reIndex`	Rebuilds all indexes on a collection.
`renameCollection`	Changes the name of an existing collection.
`repairDatabase`	Repairs any errors and inconsistencies with the data storage.
`setParameter`	Modifies configuration options.
`shutdown`	Shuts down the `mongod` or `mongos` process.
`touch`	Loads documents and indexes from data storage to memory.

Diagnostic Commands¶

Name	Description
`availableQueryOptions`	Internal command that reports on the capabilities of the current MongoDB instance.
`buildInfo`	Displays statistics about the MongoDB build.
`collStats`	Reports storage utilization statics for a specified collection.
`connPoolStats`	Reports statistics on the outgoing connections from this MongoDB instance to other MongoDB instances in the deployment.
`cursorInfo`	Reports statistics on active cursors.
`dataSize`	Returns the data size for a range of data. For internal use.
`dbHash`	Internal command to support sharding.
`dbStats`	Reports storage utilization statistics for the specified database.
`diagLogging`	Provides a diagnostic logging. For internal use.
`driverOIDTest`	Internal command that converts an ObjectID to a string to support tests.
`features`	Reports on features available in the current MongoDB instance.
`getCmdLineOpts`	Returns a document with the run-time arguments to the MongoDB instance and their parsed options.
`getLog`	Returns recent log messages.
`hostInfo`	Returns data that reflects the underlying host system.
`indexStats`	Experimental command that collects and aggregates statistics on all indexes.
`isSelf`	Internal command to support testing.
`listCommands`	Lists all database commands provided by the current `mongod` instance.
`listDatabases`	Returns a document that lists all databases and returns basic database statistics.
`netstat`	Internal command that reports on intra-deployment connectivity. Only available for `mongos` instances.
`ping`	Internal command that tests intra-deployment connectivity.
`profile`	Interface for the database profiler.
`serverStatus`	Returns a collection metrics on instance-wide resource utilization and status.
`top`	Returns raw usage statistics for each database in the `mongod` instance.
`validate`	Internal command that scans for a collection’s data and indexes for correctness.
`whatsmyuri`	Internal command that returns information on the current client.

Internal Commands¶

Name	Description
`_migrateClone`	Internal command that supports chunk migration. Do not call directly.
`_recvChunkAbort`	Internal command that supports chunk migrations in sharded clusters. Do not call directly.
`_recvChunkCommit`	Internal command that supports chunk migrations in sharded clusters. Do not call directly.
`_recvChunkStart`	Internal command that facilitates chunk migrations in sharded clusters.. Do not call directly.
`_recvChunkStatus`	Internal command that returns data to support chunk migrations in sharded clusters. Do not call directly.
`_replSetFresh`	Internal command that supports replica set election operations.
`_transferMods`	Internal command that supports chunk migrations. Do not call directly.
`handshake`	Internal command.
`mapreduce.shardedfinish`	Internal command that supports map-reduce in sharded cluster environments.
`replSetElect`	Internal command that supports replica set functionality.
`replSetGetRBID`	Internal command that supports replica set operations.
`replSetHeartbeat`	Internal command that supports replica set operations.
`writeBacksQueued`	Internal command that supports chunk migrations in sharded clusters.
`writebacklisten`	Internal command that supports chunk migrations in sharded clusters.

Testing Commands¶

Name	Description
`_hashBSONElement`	Internal command. Computes the MD5 hash of a BSON element.
`_journalLatencyTest`	Tests the time required to write and perform a file system sync for a file in the journal directory.
`captrunc`	Internal command. Truncates capped collections.
`configureFailPoint`	Internal command for testing. Configures failure points.
`emptycapped`	Internal command. Removes all documents from a capped collection.
`forceerror`	Internal command for testing. Forces a user assertion exception.
`godinsert`	Internal command for testing.
`replSetTest`	Internal command for testing replica set functionality.
`skewClockCommand`	Internal command. Do not call this command directly.
`sleep`	Internal command for testing. Forces MongoDB to block all operations.
`testDistLockWithSkew`	Internal command. Do not call this directly.
`testDistLockWithSyncCluster`	Internal command. Do not call this directly.

MongoDB Manual 2.4

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