This is the second post in my mini-series on leveraging SQL Developer Reports for DBA tasks, today with visualizing Average Active Sessions (AAS). In this article I’ll cover
- What AAS is and how to interpret it
- How to build a basic line graph in SQL Developer
- How to extend the graph with detailed child reports (Time Model Statistics and Top Events)
If you run Oracle Standard Edition or haven’t licenced Diagnostics Pack for Enterprise Edition, then you don’t have AWR and ASH Data available. This is when Statspack, the predecessor of AWR, comes in handy to keep a history of database performance metrics.
But although Oracle still deliver Statspack with their recent DB releases (yes, even in 12c it’s not dead!), there are few tools that support it. But wait – Oracle SQL Developer has a nice reporting feature built in, so why not build custom statspack reports for this great free tool?
This motivated me to start a series on leveraging SQL Developer Reports for DBA tasks, starting with visualizing logical I/O history.
First things first:
Thou shalt not explicitly set AQ_TM_PROCESSES=0 !
Unless, of course, you want to disable the Queue Manager Process (QMNC in Oracle 11.x). Which you may want to do during database upgrades to prevent Streams or Advanced Queueing from interfering with the upgrade process.
However, if you don’t reset this parameter afterwards, you might run into the following scenario the next time you do a Data Pump export or import: