The Bestway to copy data between data from one database to another database is based on the size of the data.

For ex:

If you want to copy the data from one table to another and the data size is not more then you can copy data by using
copy command and db link.

But if data is more then do export/import.

In your subject you mentioned HTTP transfer, I did't understand that question? If you give me some more details on your job i can giveyou the complete steps. Good Luck.