You have a use case that requires a large data extract, which is more than...

Send the file as a multipart attachment to an OIC integration using a REST trigger, and make it available for processing using a Stage File action.

Retrieve the file by invoking a SOAP API, which sends Base64 encoded data within the SOAP body, and then decode the data and make it available for processing using a Stage File action.

Retrieve the file by invoking a SOAP API, which sends the document as an MTOM attachment, and make it available for processing using a Stage File action.

Retrieve the file from an external endpoint using APIs that support application/blob as content type, and make it available for processing using a Stage File action.

Upload the file to the OIC file server, and then use an FTP adapter Download File operation, which makes it available for processing using a Stage File action.