Is the performance of upsert getting worse as the number of documents increases? what if it s insert? Wouldn t there be any of the above problems? I now have a scenario of writing more and reading less. How to ensure the optimal write speed, and as ...
If a new document is added to mongodb, does it have the ability to actively notify the application? For example, if a queue set adds a pending task, can mongobd actively notify the application to perform the processing instead of constantly polling and c...
some problems were found when querying the slow query log of online MongoDB today question 1 the total number of tables is 1007422 but you see this output keysExamined:4946620 docsExamined:1007409 how can keysExamined exceed the total? quest...
the data in the database is like this. There are decimals, and I need to sum them. execute the following code: bet.aggregate( { $match: { state: { $in: [0, 1, 2, 3] } } }, { $group: { _id: { state: "$state" ...
there was an error installing brew install mongodb on Mac. Do you need to clear the historical data and reinstall ...
Ajax code of the front end: ** * Created by Administrator on 2018 4 17. * $(function() { var $loginBox = $( -sharploginBox ); var $registerBox = $( -sharpregisterBox ); var $userInfo = $( -sharpuserInfo ); $loginBox....
there was an error installing brew install mongodb on Mac. The directory usr local opt pkg-config could not be found ...
in my collection, has related different documents, and only one field is different between them, assuming field . how to merge different related documents into one document and turn this field into an array of fields [], is it done through aggregat...
Ajax Code: $(function () { var $register = $(".register"); var $login = $(".login"); $login.find(".submit").on( click ,function () { }); $register.find( button ).on( click , function(){...
delete a folder of mongoDB, and then always report an error when you want to install it. It s supposed to be because mongoDB didn t uninstall cleanly. But in the uninstall program to find do not hit mongoDB, want to uninstall through PC manager s unin...
What data type is the best way to store foreign key id in mongodb? For example, in an article, if you want to store the user id, the foreign key id of the user, should you use the String type or the ObjectId type? ...
Collection a has the following documents: { "_id" : ObjectId("5acd77c763c9b117b48b2e92"), "Symbol" : "item01", "min5" : [ { "Symbol" : "item01", ...
set up a test set one, which has 100 million documents and about 6.3G document data. A total of three indexes have been established. As shown in the figure above, the three indexes are all in the size of 1G, and the three indexes have a total size of...
...
const MongoClient = require( mongodb ).MongoClient; const url = mongodb: localhost:27017 ; Database Name const dbName = youyue ; var obj = {}; module.exports = async(ctx,next)=>{ const num = ctx.query.num, page = ctx.query.pag...
there is a requirement in the project that a field extracted from the mongodb library at the level of tens of millions of records needs to be transferred to postgresql. because the mongodb is constantly updated, the data needs to be reversed at regular...
mongoose What is the reason for ? ...
mongodb $set updates different fields of the same document, resulting in dirty data? High concurrency may update different fields at the same time, such as two people updating at the same time, A updating field one, B updating field two. Is it possible...
query router.get(" cartList", (req, res, next) => { User.findOne({ userId: 123456 }, (err, doc) => { }); } query router.get(" cartList", (req, res, next) => { let userId = req.cookies.userId console.log(user...
paste the original data document first: : : what I want to ask is why the day1 update is successful, but day2.time1 can not update the callback of, save (), and how can it be updated successfully without err,? ...
if the premise height is not set or auto,min-heigth is not suitable, there will be a blank at the bottom. .errors { width: 390px; min-height: 210px; background:white; position: fixed; top: 0; right: 0; bottom: 0; left: 1...
I want these two subcomponents to be displayed in div1. What should I do if I can only write one and write two at the same time? <!DOCTYPE html> <html> <head> <title>< title> <script src="vue.js"><...
A customer, who used to be a member who manages his store on the micro-life merchant platform, later wanted to use another cashier system (.net) to make a cashier. The micro-living platform provides api documents, and the interface data of transaction co...
there is no response from axios get or post, and there is no output from then or catch. Other browsers on the same phone are (UC), and Wechat debugging tools, PC browsers, local environment, and chrome simulation of Wechat are all fine. my phone is Xi...
what needs to be configured in the weex project before the situation in the figure ...