Oracle — Table lock modes
1 min readJan 18, 2019
Here is a post with a few links to previous blog/article/video about Oracle table lock modes. And remember that in 12cR2 the event 10704 has been replaced by UTS tracing:
alter session set events 'trace[ksq] disk medium';
1. An explanation of the compatibility matrix (RS, RX, Share, SSX, X):
2. the KSD tracing to see which locks are acquired:
3. A presentation on table locks:
Agenda was:
- 0:45 — Basics
- 5:03 — TX lock demo
- 9:30 — TM lock info
- 21:04 — Foreign key index demo
- 28:48–10g, 11g, 12c locking differences
- 41:50 — New online operations in 12c
- 46:26 — Event 10704 trace
- 50:34 — Deadlock demo
- 53:42 — Q&A
The slides seem to be there: