I've been looking at the init parms that should affect Shared Server Sessions, and each one mentions that I should look at others, and those point to others, etc. Are there any suggestions on which of these are more important, so I can start with those? We're running 10g, and have the SGA and PGA set to auto-tune themselves.

I ask this only because we get two effects:
- connect times are longer for SHARED connections vs DEDICATED (5-20 secs vs 1-2 secs)
- query run times will jump from 30msec to as long as 20 secs for the same query issued in quick succession for SHARED connections. DEDICATED run right around the 30msec mark each time.