> db.foo.insert({a:1,b:"hello"})
WriteResult({ "nInserted" : 1 })
> db.foo.ensureIndex({b:"text",a:1})
WriteResult({ "nInserted" : 1 })
> db.foo.find({a:1,$text:{$search:"hello"}},{_id:0,a:1}).explain()
{
	"cursor" : "TextCursor",
	"n" : 1,
	"nscannedObjects" : 0, // Good: text index correctly covers this query
	"nscanned" : 1,
	"nscannedObjectsAllPlans" : 0,
	"nscannedAllPlans" : 1,
	"scanAndOrder" : false,
	"nYields" : 0,
	"nChunkSkips" : 0,
	"millis" : 0,
	"server" : "Rassi-MacBook-Pro.local:27017",
	"filterSet" : false
}
> db.foo.dropIndexes()
{
	"nIndexesWas" : 2,
	"msg" : "non-_id indexes dropped for collection",
	"ok" : 1
}
> db.foo.ensureIndex({a:1,b:"text"})
WriteResult({ "nInserted" : 1 })
> db.foo.find({a:1,$text:{$search:"hello"}},{_id:0,a:1}).explain()
{
	"cursor" : "TextCursor",
	"n" : 1,
	"nscannedObjects" : 1, // Bad: text index should be able to cover this query
	"nscanned" : 1,
	"nscannedObjectsAllPlans" : 1,
	"nscannedAllPlans" : 1,
	"scanAndOrder" : false,
	"nYields" : 0,
	"nChunkSkips" : 0,
	"millis" : 0,
	"server" : "Rassi-MacBook-Pro.local:27017",
	"filterSet" : false
}
>