Query on sharding the collection and database

[Akshaya_Srinivasan]

From MongoDB documentation I see that only if the database has sharding enabled, a collection in it can be sharded.
Say if I have a database with 10 collections and I want to enable sharding on one collection in it. If I enable sharding for the database and that one collection, will the other 9 collections be sharded too?
Also if I add few more collections to that database, will the newly added collections be sharded too?

Thanks,
Akshaya Srinivasan

[steevej (Steeve Juneau)]

Only collections for which you enable sharding with sh.shardCollection() will be sharded.

When you shard you must specify a shard key. There is no way for the system to know which shard key should be use. So by default collections are not sharded.