Sends back a entire backup archive part as raw binary data stream, i.e. a regular file download
The numeric ID of the backup record whose files you want to download
The backup part you wish to download. For example, if we have a multi-part archive with the base name test.jpa and six parts (.j01 through .j05 and .jpa) then part_id=2 means that we want to download test.j02 and part_id=6 means that we want to download the last part, i.e. test.jpa. If the backup record is not a multi-part archive just use 1.
Unencrypted binary stream containing the raw file data. You will also receive standard HTTP headers setting the content disposition to Attachment, specifying an application/octet-stream MIME type and notifying you of the size of the download. In fact, you can generate a URL and pass it to any third party download tool (e.g. cURL, Wget) to download the archive part.