text: // Simple covered index query test
  
  var coll = db.getCollection("covered_simple_id")
  coll.drop()
  for (i=0;i<10;i++) {
      coll.insert({_id:i})
  }
  coll.insert({_id:"string"})
  coll.insert({_id:{bar:1}})
  coll.insert({_id:null})
  
  // Test equality with int value
  var plan = coll.find({_id:1}, {_id:1}).hint({_id:1}).explain()
  assert.eq(true, plan.indexOnly, "simple.id.1 - indexOnly should be true on covered query")
  assert.eq(0, plan.nscannedObjects, "simple.id.1 - nscannedObjects should be 0 for covered query")
  
  // Test equality with string value
  var plan = coll.find({_id:"string"}, {_id:1}).hint({_id:1}).explain()
  assert.eq(true, plan.indexOnly, "simple.id.2 - indexOnly should be true on covered query")
  assert.eq(0, plan.nscannedObjects, "simple.id.2 - nscannedObjects should be 0 for covered query")
  
  // Test equality with int value on a dotted field
  var plan = coll.find({_id:{bar:1}}, {_id:1}).hint({_id:1}).explain()
  assert.eq(true, plan.indexOnly, "simple.id.3 - indexOnly should be true on covered query")
  assert.eq(0, plan.nscannedObjects, "simple.id.3 - nscannedObjects should be 0 for covered query")
  
  // Test no query
  var plan = coll.find({}, {_id:1}).hint({_id:1}).explain()
  assert.eq(true, plan.indexOnly, "simple.id.4 - indexOnly should be true on covered query")
  assert.eq(0, plan.nscannedObjects, "simple.id.4 - nscannedObjects should be 0 for covered query")
  
  // Test range query
  var plan = coll.find({_id:{$gt:2,$lt:6}}, {_id:1}).hint({_id:1}).explain()
  assert.eq(true, plan.indexOnly, "simple.id.5 - indexOnly should be true on covered query")
  assert.eq(0, plan.nscannedObjects, "simple.id.5 - nscannedObjects should be 0 for covered query")
  
  // Test in query
  var plan = coll.find({_id:{$in:[5,8]}}, {_id:1}).hint({_id:1}).explain()
  assert.eq(true, plan.indexOnly, "simple.id.6 - indexOnly should be true on covered query")
  assert.eq(0, plan.nscannedObjects, "simple.id.6 - nscannedObjects should be 0 for covered query")
  
  print ('all tests pass')
  