How to backup an Oracle database?

Question

Oracle

Good day to all.
Please tell me a working tool that allows you to create a fully working backup from DB A and transfer it to DB B. For example, creating backups in other DBMS (MS Sql, PostgreSQL, MySql). Is there such a tool at all that allows you to quickly and easily transfer a database between hosts (perhaps even on different OS, with different instance names, etc.), just take 1 file from both DB A and DB B to "say" - here you file, work.
All possible options are considered (including paid ones).

Answer 1

If it's a backup, then it's definitely RMAN. If dumps are needed, then either through data pumps (expdp / impdb), or, if oracle versions are old, export and import utilities (exp / imp)

Answer 2

Your question is more about data migration: https://blogs.oracle.com/russia/19c-migration

Answer 3

Within the OS of the same family (type), just a "cold" backup - copying database files.
with the creation of the corresponding init file and possibly re-creation of control files (if the paths to the database are different), also configure a listener to listen for connections to the database, while the DBMS themselves must be completely identical (the same version, bit depth, etc.)
PS: maybe not the fastest way, but the easiest.
PPS: if you transfer between different versions of the DBMS and OS, then IMHO, only exp / imp
can still transfer data via links or bicycle file replications (but this is between working databases with a data structure) ...