Hi,

1.while using dbv, i got message that
"specified blocksize 2048 deffers from actual 8192"
what can i do?

2. how to recover if online rollback regment is lost?

3.while checking wait evet, there a many with "rdbms ipc" time out, is it a problem?Also what is difference from column i got : p1text with "duration,time out,sleep time,driver id"

4. how to solve locking problem?

If u a confused too, keep watch!

is it too hard?

1. add blocksize=8192 in your command
2.http://61.144.248.54:1521/oracle/recover_rbs.html
3.normally, ' rdbms ipc message' is not an important event ,  too much timeouts just means this database is not busy .( someone correct me)
addon:  look at oracle online doc. about the definition of p1text.

4. http://61.144.248.54:1521/oracle/lock_concept.html

HTH

Very concise and detailed! really helpful!
Since u a expert, can u solve those Qs for me?

1. suppose while a archive process is running, and there is a crash, u lost ur current archive log file...
can u make a full recover? will u lose the data?

2. for tuning, what a most important(or the 1st step) i need to do?

THKS, I am reading the  materials of ur website,really nice!

1.because  archived log is an backup of the online log , if the current and active online log are intact , you can make a full recovery .
2.for tuning , the most important is finding the bad SQL . I also suggest you use statspack ( in $ORACLE_HOME/rdbms/admin/stats*.doc if you use 8.1.6) or bstat/estat to make life easy .

Thanks for your overpraising , if I were expert , I should not work overtime all the time.

By the way, is there dba who need  not to work overtime?

Still u a much advanced than me   

keep contact!