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 |