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Why Don Burleson's "get_busy.ksh" does'nt work? [message #64893] Thu, 26 February 2004 18:17 Go to next message
Tian Maohuai
Messages: 23
Registered: December 2003
Junior Member
In the Don's book "Oracle High-Performance Tuning with STATSPACK",a script called "get_busy.ksh",it says:

select ... from v$session_wait a,dba_data_files b where a.pl=b.file_id

but I see that the data of a.pl and b.file_id will never equal,the a.pl is very big,and b.file is small,how can they equal?

who knows why?
Re: Why Don Burleson's "get_busy.ksh" does'nt work? [message #64901 is a reply to message #64893] Sun, 29 February 2004 04:49 Go to previous messageGo to next message
Thiru
Messages: 1089
Registered: May 2002
Senior Member
Hi,
For an event wait like 'buffer busy waits' , v$session_wait.P1 should reflect the file_id . P1,P2,P3 of v$session_wait changes depending on the actual 'wait' that is happening at that time. P1 will not be equal to the file# always. It might indicate something else , for a different wait.

for eg)
thiru@9.2.0:SQL>select * from v$event_name where name in ('buffer busy waits');

    EVENT# NAME                           PARAMETER1
---------- ------------------------------ ------------------------------------------
PARAMETER2                                                       PARAMETER3
---------------------------------------------------------------- -------------------
       145 buffer busy waits              file#
block#                                                           id

-- as seen above, for buffer busy wait,P1 is file#

thiru@9.2.0:SQL>select * from v$event_name where name in ('latch free');

    EVENT# NAME                           PARAMETER1
---------- ------------------------------ --------------------------------------
PARAMETER2                                                       PARAMETER3
---------------------------------------------------------------- ---------------
         3 latch free                     address
number                                                           tries

-- for latch free event ,P1 is 'address'

Re: Why Don Burleson's "get_busy.ksh" does'nt work? [message #64906 is a reply to message #64901] Mon, 01 March 2004 00:55 Go to previous messageGo to next message
Tian Maohuai
Messages: 23
Registered: December 2003
Junior Member
Thank you,Thiru.I think you're right,but I can't get the result anyway.
Re: Why Don Burleson's "get_busy.ksh" does'nt work? [message #64908 is a reply to message #64906] Mon, 01 March 2004 02:52 Go to previous message
Thiru
Messages: 1089
Registered: May 2002
Senior Member
You are not getting the result becos you may not be experiencing waits at the time you run this query.

BTW,I dont use Don Burelson's scripts .

-Thiru
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