比较官方的说法

Full

A backup of a datafile that includes every allocated block in the file being backed up. A full backup of a datafile can be an image copy, in which case every data block is backed up. It can also be stored in a backup set, in which case datafile blocks not in use may be skipped, according to rules in Oracle Database Backup and Recovery Reference.

A full backup cannot be part of an incremental backup strategy; that is, it cannot be the parent for a subsequent incremental backup.

Incremental

An incremental backup is either a level 0 backup, which includes every block in the file except blocks compressed out because they have never been used, or a level 1 backup, which includes only those blocks that have been changed since the parent backup was taken.

A level 0 incremental backup is physically identical to a full backup. The only difference is that the level 0 backup is recorded as an incremental backup in the RMAN repository, so it can be used as the parent for a level 1 backup.

网上搜到的只言片语

The only difference between a level 0 backup and a full backup is that a full backup is never included in an incremental strategy. If no level 0 backup exists when you run a level 1 or higher backup, RMAN makes a level 0 backup automatically to serve as the base.

增量备份0级与全备份都是全备份,但是增量备份0级使用rman备份的话就只备份了used block,而全备份备份了used and unused block

总结一下,二者有两个地方不同

1

全备份不能被用作1级增量备份的基础

2

使用rman备份的时候,全备份备份了used and unused block,0级使用rman备份的话就只备份了used block