With multipart upload, you split the object you want to upload into individual parts. Individual parts can be as large as 50 GiB or as small as 10 MiB. (Object Storage waives the minimum part size restriction for the last uploaded part.) Decide what part number you want to use for each part. Part numbers can range from 1 to 10,000. You do not need to assign contiguous numbers, but Object Storage constructs the object by ordering part numbers in ascending order.
The maximum size for an uploaded object is 10 TiB
While a multipart upload is still active, you can keep adding parts as long as the total number is less than 10,000.
https://docs.cloud.oracle.com/en-us/iaas/Content/Object/Tasks/usingmultipartuploads.htm