CODEWITHSUNDEEP
mongodbmongoose
zb22
zb22

Reputation: 3231

Which approach is better?

I want to create a collection for user's rating, I have doubts between 2 structures schemas.

First schema:

var Rating = new mongoose.Schema({
userID: {
    type: String,
    minlength: 1,
    required: true,
    trim: true
},
ratings: [{
    rate: {
        type: Number
    }
  }]
});

Second schema:

var Rating = new mongoose.Schema({
userID: {
    type: String,
    required: true,
},
rating: {
    type: Number,
    required: true
 }, 
});

The first schema will cause that every rating the be pushed into the array of ratings and the second will cause inserting multiple documents of the same userID and each document contains its rating.

I would like to know which approach is recommended between the two, increasing the array or increasing documents each time the user get rating.

Upvotes: 0

Views: 27

Answers (1)

Neodan
Neodan

Reputation: 5242

It depends on the details of your project (there is no the one super good and universal schema).

The first structure is closer to the MongoDB ideology. But do not forget about the document size limitation (16MB, except if you are using GridFS). This structure is better if you do not have a big amount of information (items in the ratings field). Because all ratings will be in one document it means that your indexes will be optimal small (one user - one document).

The second schema is better for situation when ou have a big amount of ratings (related to the document size limit).

Also you can use two collections. One for aggregated data (final results after calculations, something like as cache) and another for detailed information. As mentioned before - the best solution depends on the details of the project

I recoment you to read this article 6 Rules of Thumb for MongoDB Schema Design

Upvotes: 1

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