Yesterday I made my first presentation ever at the annual Hotsos conference. The topic: “All of the Performance Tuning Features in SQL Developer.”
It went pretty well, and I’d like to share those slides now with y’all:
Easier to Read Autotrace Execution Plans
Apparently I said ‘explain plan’ too many times in the session…EXECUTION Plans can be quite big. And the problematic bits generally come down to one or two steps. So, for version 4.1, we’re going to highlight the ‘Hot Spots.’
The Hotspots are categorized as having:
- Nodes where cardinality estimation is wrong as witnessed by collected runtime statistics. The node with maximum discrepancy is formally a hotspot. One course of action for performance analyst to follow is adjusting cardinality estimation (e.g. with a hint), thus influencing the optimizer to choose a different plan.
- Nodes where the execution have spent bulk of the time. Formally, we take cumulative run time of a node (v$sql_plan_statistics.last_elapsed_time) and subtract cumulative run time of it’s children.
This feature will be available for you to check out for yourself in our 4.1 Early Adopter 2 update – which will be available soon.
As for making plans themselves easier to read, that’s on our product ‘to do’ list for a future release.