Need critique on my Process-Oriented Perfmon

Yong Huang

原帖由 eagle_fan 于 2008-4-2 06:33 发表

When the database is hung, you can't get data from v$session view. Directly access SGA is much faster

I remember that the code for fetching v$session_wait has already been published

It's very true that when the database is extremely busy, you can't query anything. Sometimes you can't even connect using sqlplus. In that case, you can use an undocumented option -prelim to connect as sysdba:

sqlplus -prelim / as sysdba

so that you can at least do something like oradebug dump systemstate, or dump hanganalyze.

Directly attaching to SGA is even more undocumented. But ever since Kyle Hailey posted his code, it's no longer a big secret.

Yong Huang

Yong Huang

I made a number of changes to my article (http://yong321.freeshell.org/computer/Perfmon.html). There're some interesting points. I use this command

COLUMNS=132 top -cb ...

to get full UNIX command line (up to some limit). I added a paragraph discussing 10g ASH and AWR. Added some footnotes.

Yong Huang