On the Time-consuming Problem of mongodb

  mongodb, question

Query code:

Time ('timer1')
 collection.count({}, function(err, count) {
 collection.find({}, {
 limit: num,
 skip: (data.page - 1) * num
 time: -1
 }).toArray(function(err, list) {
 var page = {}
 page["count"] = count
 page["limitNum"] = num
 callback(null, list, page)
 Timeend ('timer1')


Above, this is the mongo time-consuming time I monitored under window again.

The following figure shows the time I spent under linux.

Why do the same query codes differ by almost 3 times? My data volume is only 67

I found the reason, because the account password is set. I think mongo will verify the account password every time I request it, which takes a long time and drops to about 30ms after removing it.