How to rebuild all the indexes of a collection using PyMongo? (original) (raw)

Last Updated : 7 Jul, 2025

**Rebuilding indexes in a MongoDB collection helps optimize performance particularly after large write or update operations. In PyMongo, index rebuilding can be done using **db.command() which is the recommended way to trigger index rebuilding in modern MongoDB versions. This process drops and recreates all indexes, ensuring they remain efficient and up-to-date for query execution.

Syntax

db.command('reIndex', <collection_name>)

**Parameter:

• **reIndex: command that tells to rebuild all indexes.
• ****<collection_name>:** name of the collection (as a string) whose indexes should be rebuilt.

Sample of Collection

Snapshot of Terminal showing Sample Collection

Example 1:

This code uses **db.command() to rebuild all indexes on the **Student collection.

Python `

from pymongo import MongoClient

client = MongoClient('localhost', 27017) db = client['GFG'] collection_name = 'Student'

Rebuild all indexes on the 'Student' collection

result = db.command('reIndex', 'Student') print(result)

`

**Output

Output after Rebuilding Indexes

Example 2:

In this Example, new students documents are inserted into the **Student collection and then uses the **db.command() method to rebuild all indexes on the collection.

Python `

from pymongo import MongoClient

client = MongoClient("mongodb://localhost:27017/") db = client["GFG"] collection = db["Student"]

Insert some new records

students = [ {"_id": 10, "name": "Ankit", "Roll No": "1021", "Branch": "CSE"}, {"_id": 11, "name": "Neha", "Roll No": "1022", "Branch": "IT"} ] collection.insert_many(students)

Print only the newly inserted documents

print("Newly inserted documents:") for doc in collection.find({"_id": {"$in": [10, 11]}}): print(doc)

Rebuild indexes

result = db.command("reIndex", "Student")

#Printing rebuilded indexes print("Reindex result:") print(result)

`