PyMongo Cursor batch_size 一次返回一个文档

Question

I am trying to query a mongoDB with batch sizes. When I apply the batch_size argument in .find() method, It returns the same thing as using no batch size. The code below returns one document at a time instead of the expected batch size.

#MongoDB Connection
...
cursor = collection.find({'Time':{'$gt':58006}}, {'V1':1, 'V2':1}, batch_size=9)
for i in cursor: 
    print(i)

Answer 1

https://www.mongodb.com/docs/manual/reference/method/cursor.batchSize/ details the use of batch size.

Specifies the number of documents to return in each batch of the response from the MongoDB instance. In most cases, modifying the batch size will not affect the user or the application, as mongosh and most drivers return results as if MongoDB returned a single batch.

If you just want to get n documents, use limit() . https://pymongo.readthedocs.io/en/stable/api/pymongo/cursor.html#pymongo.cursor.Cursor.limit