Database commands

HCL OneDB™ supports a subset of the MongoDB database commands.

The basic syntax for database commands in the mongo shell is db.command(), where db refers to the current database, and command is the database command. You can use the mongo shell helper method db.runCommand() to run database commands on the current database.

User commands
Database operations

User commands

Aggregation commands

Table 1. Aggregation commands
MongoDB command	JSON collections	Relational tables
aggregate	Yes	Yes
count	Yes	Yes
distinct	Yes	Yes
group	No	No
mapReduce	No	No

Geospatial commands

Table 2. Geospatial commands
MongoDB command	JSON collections	Relational tables	Details
geoNear	Yes	No	Supported for the GeoJSON format. The MongoDB legacy coordinate pairs are not supported.
geoSearch	No	No
geoWalk	No	No

Query and write operation commands

Table 3. Query and write operation commands
MongoDB command	JSON collections	Relational tables	Details
delete	Yes	Yes
eval	No	No
find	Yes	Yes
findAndModify	Yes	Yes	For relational tables, the findAndModify command is supported only for tables that have a primary key. This command does not support sharded data.
getLastError	Yes	Yes
getMore	Yes	Yes
getPrevError	No	No
insert	Yes	Yes
resetError	No	No
update	Yes	Yes

Database operations

Authentication commands

Table 4. Authentication commands
Name	Supported	Details
authenticate	Yes
logout	Yes
getnonce	Yes

User management commands

Table 5. User management commands
Name	Supported	Details
createUser	Yes
dropAllUsersFromDatabase	Yes
dropUser	Yes
grantRolesToUser	Yes
revokeRolesFromUser	Yes
updateUser	Yes
usersInfo	Yes

Role management commands

Table 6. Role management commands
Name	Supported	Details
createRole	Yes
dropAllRolesFromDatabase	Yes
dropRole	Yes
grantPrivilegesToRole	Yes
grantRolesToRole	Yes
invalidateUserCache	No
rolesInfo	Yes
revokePrivilegesFromRole	Yes
revokeRolesFromRole	Yes
updateRole	Yes

Diagnostic commands

Table 7. Diagnostic commands
Name	Supported	Details
buildInfo	Yes	Whenever possible, the HCL OneDB output fields are identical to MongoDB. There are additional fields that are unique to HCL OneDB.
collStats	Yes	The value of any field that is based on the collection size is an estimate, not an exact value. For example, the value of the field 'size' is an estimate.
connPoolStats	No
cursorInfo	No
dbStats	Yes	The value of any field that is based on the collection size is an estimate, not an exact value. For example, the value of the field 'dataSize' is an estimate.
features	Yes
getCmdLineOpts	Yes
getLog	No
hostInfo	Yes	The `memSizeMB`, `totalMemory`, and `freeMemory` fields indicate the amount of memory that is available to the Java™ virtual machine (JVM) that is running, not the operating system values.
indexStats	No
listCommands	Yes
listDatabases	Yes	The value of any field that is based on the collection size is an estimate, not an exact value. For example, the value of the field 'sizeOnDisk' is an estimate. The listDatabases command estimates the size of all collections and collection indexes for each database. However, relational tables and indexes are excluded from this size calculation. Important: The listDatabases command performs expensive and CPU-intensive computations on the size of each database in the HCL OneDB instance. You can decrease the expense by using the sizeStrategy option. sizeStrategy You can use this option to configure the strategy for calculating database size when the listDatabases command is run. `sizeStrategy:` { { `estimate` \| `{` `estimate:n}` \| `compute` \| `none` \| `perDatabaseSpace` } } estimate Estimate the size of the documents in the collection by using 1000 (or 0.1%) of the documents. This is the default value. The following example estimates the collection size by using the default of 1000 (or 0.1%) of the documents: `db.runCommand({listDatabases:1, sizeStrategy:"estimate"})` estimate: `n` Estimate the size of the documents in a collection by sampling one document for every `n` documents in the collection. The following example estimates the collection size by using sample size of 0.5% or 1/200th of the documents: `db.runCommand({listDatabases:1, sizeStrategy:{estimate:200}})` compute Compute the exact size of each database. `db.runCommand({listDatabases:1, sizeStrategy:"compute"})` none List the databases but do not compute the size. The database size is listed as 0. `db.runCommand({listDatabases:1, sizeStrategy:"none"})` perDatabaseSpace Calculate the size of a database by adding the sizes for all dbspaces, sbspaces, and blobspaces that are assigned to the tenant database. Important: The perDatabaseSpace option applies only to tenant databases that are created by the multi-tenancy feature. `db.runCommand({listDatabases:1 , sizeStrategy:"perDatabaseSpace"})`
ping	Yes
serverStatus	Yes
top	No
whatsmyuri	Yes

Instance administration commands

Table 8. Instance administration commands
Name	JSON collections	Relational tables	Details
clone	No	No
cloneCollection	No	No
cloneCollectionAsCapped	No	No
collMod	No	No
compact	No	No
convertToCapped	No	No
copydb	No	No
create	Yes	No	HCL OneDB does not support the following flags: capped autoIndexID size max
createIndexes	Yes	Yes
drop	Yes	Yes	HCL OneDB does not lock the database to block concurrent activity.
dropDatabase	Yes	Yes
dropIndexes	Yes	No	The MongoDB deleteIndexes command is equivalent.
filemd5	Yes	Yes
fsync	No	No
getParameter	No	No
killCursors	Yes	Yes
listCollections	Yes	Yes	The includeRelational and includeSystem flags are supported to include or exclude relational or system tables in the results. Default is includeRelational=true and includeSystem=false.
listIndexes	Yes	Yes
logRotate	No	No
reIndex	No	No
renameCollection	No	No
repairDatabase	No	No
setParameter	No	No
shutdown	Yes	Yes	The timeoutSecs flag is supported. In the HCL OneDB, the timeoutSecs flag determines the number of seconds that the wire listener waits for a busy client to stop working before forcibly terminating the session. The force flag is not supported.
touch	No	No

Replication commands

Table 9. Replication commands
Name	Supported
isMaster	Yes
replSetFreeze	No
replSetGetStatus	No
replSetInitiate	No
replSetMaintenance	No
replSetReconfig	No
replSetStepDown	No
replSetSyncFrom	No
Resync	No

Sharding commands

Table 10. Replication commands
Name	JSON collections	Relational tables	Details
addShard	Yes	Yes	The MongoDB maxSize and name options are not supported. In addition to the MongoDB command syntax for adding a single shard server, you can use the HCL OneDB specific syntax to add multiple shard servers in one command by sending the list of shard servers as an array. For more information, see Creating a shard cluster with MongoDB commands.
enableSharding	Yes	Yes	This action is not required for HCL OneDB and therefore this command has no affect for HCL OneDB.
flushRouterConfig	No	No
isdbgrid	Yes	Yes
listShards	Yes	Yes	The equivalent HCL OneDB command is cdr list server.
movePrimary	No	No
removeShard	No	No
shardCollection	Yes	Yes	The equivalent HCL OneDB command is cdr define shardCollection. The MongoDB unique and numInitialChunks options are not supported.
shardingState	No	No
split	No	No

For more information about the MongoDB features, see http://docs.mongodb.org/manual/reference/.