Hi,
I am trying to improve count using covered queries but its taking ~5sec to return the response.

Is this behavior expected or there is something I can do to improve this.

Please find details below-

There is collection with 6 million records

consider each document to be something like this

i have a single field index on "type"

 when I execute following command
db.test.explain("executionStats").find({type:{$in:["test","test1","test2"]}},{type:1,_id:0}).count()

the number of keys examined are ~5.9 million
number of docs examined are 0
even though there are no docs examined i.e nothing is loaded from disk
and the query is using only index the count is taking ~5sec
Please let me know if there is anything that can be done to improve count response time.