convertShardKeyToHashed
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Description
convertShardKeyToHashed(<Object>)Returns the hashed value for the input. The
convertShardKeyToHashed()method uses the same hashing function as the hashed index and can be used to see what the hashed value would be for a key.
Example
Consider a sharded collection that uses a hashed shard key [1]
use test db.orders.createIndex( { _id: "hashed" } ) sh.shardCollection( "test.orders", { _id : "hashed" } )
If the following document exists in the collection, the hashed value of
the _id field is used to distribute the document:
{ _id: ObjectId("5b2be413c06d924ab26ff9ca"), "item" : "Chocolates", "qty" : 25 }
To determine the hashed value of _id field used to distribute the
document across the shards, you can use the
convertShardKeyToHashed() method:
convertShardKeyToHashed( ObjectId("5b2be413c06d924ab26ff9ca") )
| [1] | If the collection already contains data, you must create a hashed
index on the shard key before you shard the collection. For an empty
collection, MongoDB creates the index as part of
sh.shardCollection(). |