splitkey not working

[bbnsumanth]

I'm using the following code to get data using a split key on pid. But unfortunately, spark is fetching all the data from MongoDB collection.Can someone say me where I'm going wrong.
val mongoConfig = MongodbConfigBuilder(
Map(
Host -> mongoHost,
Database -> mongoDatabase,
Collection -> mongoCollection,
SamplingRatio -> 1.0,
WriteConcern -> "normal",
SplitSize -> "5",
SplitKey -> "pid",
SplitKeyMin -> "357",
SplitKeyMax -> "368",
SplitKeyType -> "int"
)
).build()
val df = spark.sqlContext.fromMongoDB(mongoConfig)

[bbnsumanth]

I found the reason for this problem,there is no index on "pid" field in my mongoCollection.I would be very helpful if this is included in the documentation.