Matt Rittman has a good review of a talk by Mogens on the different tuning methods and some comments about technology.
Tim Gorman had a talk about using the analytical functions LEAD/LAG to make statspack or AWR snapshots into a datawarehouse. Allowing you to track the performance of SQL across time. This allows you to identify the troublemakers that Mogens is talking about.
This link contains the whitepaper and slides from his talk to RMOUG.
Identifying and removing troublesome SQL before it becomes a problem is proactive tuning. Rather than let SQL build up and become a performance issue and then REACT, it is better to find and handle early.
This is a same for capacity planning. This task allows you to track the growth of tables, and extrapolate where they will be. Combining the growth data with performance data allows your to see what the impact of table growth is having on performance.
The scripts I have developed on SQLserver which use SQL profiler to capture SQL performance allow me to perform a similar process (although with much less metrics) and track the performance over time.
On a sidenote: Daylight savings went off without a problem after we implemented the blackout schedule for logshipping. Everything I read indicated that there wasn't a problem going backwards for the SQL Agent (next_date is the problem) however I was better to be safe then sorry.
Have Fun
Related: Automatic SQL Profiler
