db.{collection}.ensureIndex({ fieldA: 1, "nested.B": 1, "nested.C": 1 })
db.{collection}.find({ fieldA: "abc", "nested.B": "123", "nested.C": "456"})
Only uses first two index fields and then individually scans all matching items for "nested.C": 1.
db.{collection}.find({ fieldA: "abc", "nested": { $elemMatch: { "B": "123", "C": "456" } })
| root@login:/home/vagrant# perf script | |
| # ======== | |
| # captured on: Tue Nov 24 10:13:31 2015 | |
| # hostname : login | |
| # os release : 3.13.0-57-generic | |
| # perf version : 3.13.11-ckt21 | |
| # arch : x86_64 | |
| # nrcpus online : 4 | |
| # nrcpus avail : 4 | |
| # cpudesc : Intel(R) Core(TM) i7-4558U CPU @ 2.80GHz |
I hereby claim:
To claim this, I am signing this object:
The prep-script.sh will setup the latest Node and install the latest perf version on your Linux box.
When you want to generate the flame graph, run the following (folder locations taken from install script):
sudo sysctl kernel.kptr_restrict=0
# May also have to do the following:
# (additional reading http://unix.stackexchange.com/questions/14227/do-i-need-root-admin-permissions-to-run-userspace-perf-tool-perf-events-ar )
sudo sysctl kernel.perf_event_paranoid=0
| import * as Rx from 'rx'; | |
| const kSubject = Symbol('subject'); | |
| export default class EventAggregator { | |
| constructor(){ | |
| this[kSubject] = new Rx.Subject(); | |
| } | |
| publish(event, payload){ |
| const express = require('express') | |
| const jwt = require('express-jwt'); | |
| const dotenv = require('dotenv'); | |
| const constants = require('./constants'); | |
| const sandcastle = require('sandcastle'); | |
| dotenv.config(); | |
| const app = express() | |
| const port = constants.PORT |