public MongoCommandCursor MongoCommandCursor::batchSize    ( int $batchSize   )

MongoCommandCursor::batchSizeLimits the number of elements returned in one batch

batchSize

The number of results to return per batch. Each batch requires a round-trip to the server.

This cannot override MongoDB's limit on the amount of data it will return to the client (i.e., if you set batch size to 1,000,000,000, MongoDB will still only return 4-16MB of results per batch).