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shardCollection¶
-
shardCollection
¶ The
shardCollection
command marks a collection for sharding and will allow data to begin distributing among shards. You must runenableSharding
on a database before running theshardCollection
command.This enables sharding for the collection specified by
<collection>
in the database named<db>
, using the key<shardkey>
to distribute documents among the shard.<shardkey>
is a document, and takes the same form as an index specification document.Choosing the right shard key to effectively distribute load among your shards requires some planning.
See also
Sharding for more information related to sharding. Also consider the section on Shard Key Selection for documentation regarding shard keys.
Warning
There’s no easy way to disable sharding after running
shardCollection
. In addition, you cannot change shard keys once set. If you must convert a sharded cluster to a standalone node or replica set, you must make a single backup of the entire cluster and then restore the backup to the standalonemongod
or the replica set..