Questions tagged [MongoDB] (1430)

Error: UnhandledPromiseRejectionWarning: Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client This happens when sending json from the Postman to the server on node.js. At the same time in a DB in MongoDB data is entered How to get rid of the error? I don't even understand its essence.

Is blocked if the read\write speed when saving to disk? And pumps if mongo data in memory as radishes when restarting, or they remain on the disk ?

Hello! Started new project with no database schema, but over time of collections is a lot and I feel like I start to get confused) please Tell me with which program can create the database schema?

There is a model:class User(AbstractUser): user_id = models.IntegerField(unique=True) appeal = models.TextField() timestamp = models.IntegerField() status = models.IntegerField() ref = models.IntegerField() btc_wallet = models.TextField() eth_wallet = models.TextField() start_sub = models.IntegerField() end_sub = m...

That is, if the front comes for example blabla:true if the documents whose field bla is equal to 1, will be included in the sample, and if blabla is false will be issued to only those docks that do not include the bla:1

Faced with the challenge of designing a database for a large data set, it is about billions of records(currently 200 million). Standard solutions for such volumes start to degrade the speed of insertion/read(very important). Acceptable response time to 20 seconds, of course the sooner the better. The data are stored in a s...

Going to do a new project with the database MongoDB. Want to test in battle. Prior to this worked with PostgreSql, which, in all suits, but want of novelty. Postgres clocked to high speeds hranimoj and optimum queries with indexes. How fast Mongo against Postgres other things being equal, and whether you want it to do any o...

I now use async parallel for multiple queries, which would then, on the basis of replies to make a few more. But the question is is it right? I mean, maybe there's a way to do queries at the same time and without parallel, the forces mongoose or something native?

Hi. Comes json file. { "response": { "count": 22687, "items": [ { "id": 457263017, "album_id": -7, "owner_id": -89600892, "user_id": 100, "sizes": [ { "type": "m", "url": "https://sun1- 90.userapi.com/c850424/v850424557/xxx/BJTxSEZNPg.jpg", "width": 97, "height": 130 }, { "type": "s", "url": "https://sun1- 8...

Hi all. I have this piece of json file.{"_id": {"$oid": "5ddbeeb9634a813c8aa11895"}, "sammy": {"username": "SammyShark", "location": "Indian Ocean", "online": true, "followers": {"$numberInt": "987"}, "URL": "https://sun9-39.userapi.com/c849136/v849136007/b06d7/FMpHASyDw_Y.jpg"}, "jesse": {"username": "JesseOctopus", "locat...