Hi All,
Oracle v11.1.0.7.
I am aware that there are many threads on AWR report, but still I am putting my questions in this thread.
Host Name Platform CPUs Cores Sockets Memory(GB)
---------------- -------------------------------- ---- ----- ------- ----------
aaaaaa3484.aaaaa Linux x86 64-bit 8 8 2 31.31
(host name is masked, please ignore)
My questions are around this section. The AWR report is generated for a period of 5 hours of overnight processing
Top 5 Timed Foreground Events
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Avg
wait % DB
Event Waits Time(s) (ms) time Wait Class
------------------------------ ------------ ----------- ------ ------ ----------
db file sequential read 5,403,573 22,744 4 40.7 User I/O
DB CPU 16,612 29.7
db file parallel read 318,379 4,597 14 8.2 User I/O
log file sync 338,502 3,232 10 5.8 Commit
direct path write temp 402,351 3,053 8 5.5 User I/O
When DB CPU shows number 29.7, how can I interpret it? Is it 29.7% of total CPU time?
what is total CPU time? Is it 5hours X 8 CPUs?
Does that CPU wait means, in these 5 hours, 29.7% of time, Oracle was waiting for CPU to be allocated to Oracle's processes?
to me that means, 29.7% of time Oracle was not doing anything or I am missing something?
I know "db file sequential read" are the I/O wait when doing indexed read. Are the "db file sequential read" caused only by speed (or slowness) of the I/O system? "I/O system" and storage, are they the same thing (I guess not)??
Thanks in advance