MongoDB Estimated Document Count

MongoDB Estimated Document Count

In MongoDB, the estimatedDocumentCount operation is used to estimate the number of documents in a collection. This method is essential for quickly determining the size of a collection without performing a full count.

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Syntax

db.collection.estimatedDocumentCount(options)

The estimatedDocumentCount method takes an optional options parameter to customize the estimation.

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Example MongoDB Estimated Document Count

Let's look at some examples of how to use the estimatedDocumentCount method in the programGuru collection in MongoDB:

1. Estimate Document Count

db.programGuru.estimatedDocumentCount()

This command returns an estimate of the number of documents in the programGuru collection.

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Full Example

Let's go through a complete example that includes switching to a database, creating a collection, inserting documents, and estimating the document count.

Step 1: Switch to a Database

This step involves switching to a database named myDatabase.

use myDatabase

In this example, we switch to the myDatabase database.

Step 2: Create a Collection

This step involves creating a new collection named programGuru in the myDatabase database.

db.createCollection("programGuru")

Here, we create a collection named programGuru.

Step 3: Insert Documents into the Collection

This step involves inserting documents into the programGuru collection.

db.programGuru.insertMany([
    { name: "John Doe", age: 30, email: "john.doe@example.com" },
    { name: "Jane Smith", age: 25, email: "jane.smith@example.com" },
    { name: "Jim Brown", age: 35, email: "jim.brown@example.com" }
])

We insert multiple documents into the programGuru collection.

Step 4: Estimate Document Count

This step involves using the estimatedDocumentCount method to estimate the number of documents in the programGuru collection.

db.programGuru.estimatedDocumentCount()

We estimate the number of documents in the programGuru collection.

Conclusion

The MongoDB estimatedDocumentCount operation is crucial for quickly determining the size of a collection without performing a full count. Understanding how to use this method allows you to efficiently manage and analyze data within MongoDB collections.