Introduction to MongoDB Object.bsonSize() Method

MongoDB is a document-based NoSQL database that supports storage of multiple data types, including BSON (Binary JSON). In MongoDB, Object.bsonSize() is a method used to calculate the size of BSON objects.

Syntax

The syntax of the Object.bsonSize() method is as follows:

Object.bsonSize(obj)

Where obj is a BSON object. The method returns a number that represents the size of the passed BSON object in bytes.

Use Cases

The Object.bsonSize() method is commonly used in the following scenarios:

Evaluating document size: In MongoDB, each document must be less than 16MB. Using Object.bsonSize() can help you evaluate the size of documents to ensure they do not exceed the 16MB limit. Optimizing query performance: In MongoDB, the size of query results directly affects query performance. Using Object.bsonSize() can help you understand the size of query results and adjust as needed.

Examples

Example 1

We can use the following code to calculate the size of a BSON object:

var obj = {
  _id: ObjectId("61771d0fbd9e5b4f4b4dc52c"),
  name: "Alice",
  age: 30,
  address: {
    street: "123 Main St",
    city: "New York",
    state: "NY",
    zip: "10001"
  },
  phone: [
    {
      type: "home",
      number: "555-1234"
    },
    {
      type: "work",
      number: "555-5678"
    }
  ]
}
var size = Object.bsonSize(obj)
print(size)

Running the above code will output the following result:

188

Example 2

In the MongoDB Shell, we can use the Object.bsonSize() method to calculate the size of an object, as shown below:

> var doc = {
...    "name": "John",
...    "age": 30,
...    "address": {
...       "street": "123 Main St",
...       "city": "Anytown",
...       "state": "CA",
...       "zip": "12345"
...    },
...    "scores": [70, 80, 90],
...    "status": "A"
... }
> Object.bsonSize(doc)
64

In this example, the size of the BSON object is 64 bytes.

Conclusion

The Object.bsonSize() method is a useful tool for calculating the size of BSON objects. It can be used to evaluate the size of documents in a database and query performance, and can be used to compare the size of different BSON objects. In practical applications, it should be used according to specific scenarios.