⚙️ Oracle Database Administration – Process Architecture (Background & Server Processes)
20 questions · 15 min timer · Explanations included · Free
This is the most reliably asked Oracle interview topic there is, because it’s easy to check and hard to fake. Either you know which process writes redo and which writes data blocks, or you don’t.
What this quiz covers
- LGWR — writing the redo log buffer to the online redo logs, and when it fires
- DBWn — writing dirty buffers to datafiles, and why that isn’t the same event
- CKPT — checkpoints and the headers it updates
- PMON — recovering resources from failed user processes
- SMON — instance recovery and temporary segment cleanup
- RECO — resolving in-doubt distributed transactions
- MMON and friends — AWR snapshot collection
- QMNC — queue monitoring
- Parallel execution coordination
- RAC-specific processes — LCK, and global cache coherency
Common mistakes
- Swapping LGWR and DBWn — a commit writes redo, not data blocks
- Confusing PMON with SMON; process failure against instance recovery
- Assuming a checkpoint writes everything to disk immediately
Twenty questions below, each with an explanation.
