To dump buffer headers and buffer contents for buffers currently in the cache use:
ALTER SESSION SET EVENTS 'immediate trace name buffers level level';
where level is one of the following:
| Level | Description |
| 1 | Buffer headers only |
| 2 | Level 1 + block headers |
| 3 | Level 2 + block contents |
| 4 | Buffer headers only + hash chain |
| 5 | Level 1 + block headers + hash chain |
| 6 | Level 2 + block contents + hash chain |
| 8 | Buffer headers only + hash chain + users/waiters |
| 9 | Level 1 + block headers + hash chain + users/waiters |
| 10 | Level 2 + block contents + hash chain + users/waiters |