interpreting statspack reports ( PX Deq )

From: john <jmsalvo_at_ihug.com.au>
Date: 10 Jun 2002 01:47:19 -0700
Message-ID: <fa6269d2.0206100047.200f790e@posting.google.com>

Oracle 8i ( 8.1.7.0.0 )
Solaris 8
__NO__ Parallel Server but am using Parallel Query

I have at the top 5 of the wait events the following:

Top 5 Wait Events

~~~~~~~~~~~~~~~~~                                             Wait    
% Total
Event                                               Waits  Time (cs)

Wt Time

-------------------------------------------- ------------ ------------
-------
PX Deq Credit: send blkd                          334,105      176,389
  37.10
PX Deq: Execution Msg                              35,860       57,729
  12.14
PX Deq: Table Q Normal                            865,976       50,065
  10.53
PX Deq: Execute Reply                              22,596       46,401
   9.76
db file scattered read                            285,813       44,901
   9.44
          -------------------------------------------------------------

However, looking at the Wait Events descriptions in the Oracle8i Reference manual, I cannot find a description for the first 4 wait events above. ( I assume here that PX means parallel execution ). The only wait events listed on the manuals for parallel execution are:

parallel execution create server
parallel execution dequeue wait
parallel execution qref latch
parallel execution server shutdown
parallel execution signal server

What are these event names and what do they mean??

Also, I have the following latches with a high ratio:

                                                Pct    Avg            
    Pct
                                   Get          Get   Slps      
NoWait NoWait
Latch Name                       Requests      Miss  /Miss

Requests Miss

----------------------------- -------------- ------ ------
------------ ------
parallel query alloc buffer           24,010    3.6    0.0           
0
parallel query stats                   3,703   26.0    0.2

... but what do these 2 latch name means? and their corresponding figures?

Is there a full / comprehensive list of

event names and their meanings ( the ones I mentioned above are not in Oracle8i Reference )
latch names and their meanings

Does anyone also know of a doc to fully interpret reports generated from statspack?

Thanks

John Received on Mon Jun 10 2002 - 03:47:19 CDT