We know Windows NTFS compression on Oracle Database datafiles is a bad idea.
It prevents Asynchronous Random Disk I/O which can increase the risk of corruption and generally slow down the database.
However, we have some Oracle databases (11g & 12c) on Windows Server 2012 R2 servers with Windows file compression on the datafiles. How do we safely deactivated this file compression? Are there any watch-outs?