Curious question about physical files to store database

[Patrick Dung <patrick_dkt@xxxxxxxxxxxx>]

As I have seen, some database created or pre-allocate large physical files on the file system to as the backend of the database tablespace.

For Postgresql, I have observed that it created several files in the base and global directory.

It may be by design, what is the pros and cons of this behavior?

Thanks and regards,
Patrick