Re: "free buffer waits" under eXtreme Transaction Loads

From the 1st email:

Cache Sizes (end)
~~~~~~~~~~~~~~~~~
Buffer Cache: 768M Std Block Size: 8K
Shared Pool Size: 160M Log Buffer: 1,024K

--------------------
Hi, only for curiosity
which is your LOG_BUFFER size?
 
-------Original Message-------
 
From: oracle-l@xxxxxxxxxxxxx
Date: 07/26/04 13:29:47
To: oracle-l@xxxxxxxxxxxxx; oracledba@xxxxxxxxxxx
Subject: "free buffer waits" under eXtreme Transaction Loads
 
Folks
 
How are "free buffer waits" (below) to be addressed?
 
Case - Benchmark of OLTP Transactions(ATM Trans) of a Banking
Application
 
Machine - HP Superdome
Storage XP1024
DB Server =3D 32 CPUs (Itanium)
CPU Utilization =3D 30 % approx
 
For log file sync wait (below) we are considering assigning 4
controllers exclusively to the 4 logfiles(raw)
 
Will provide any data needed
 
Thanks
 
 
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
STATSPACK report for
 
DB Name DB Id Instance Inst Num Release Cluster Host
------------ ----------- ------------ -------- ----------- -------
------------
BMON 19538057 bmon 1 9.2.0.5.0 NO sut92
 
Snap Id Snap Time Sessions Curs/Sess Comment
------- ------------------ -------- ---------
-------------------
Begin Snap: 666 26-Jul-04 00:42:11 82 16.1
End Snap: 667 26-Jul-04 00:53:04 84 35.4
Elapsed: 10.88 (mins)
 
Cache Sizes (end)
~~~~~~~~~~~~~~~~~
Buffer Cache: 768M Std Block Size: 8K
Shared Pool Size: 160M Log Buffer: 1,024K
 
Load Profile
~~~~~~~~~~~~ Per Second Per Transaction
--------------- ---------------
Redo size: 6,159,634.77 5,678.93
Logical reads: 101,769.87 93.83
Block changes: 26,383.87 24.32
Physical reads: 11.62 0.01
Physical writes: 392.43 0.36
User calls: 33,233.83 30.64
Parses: 3,261.30 3.01
Hard parses: 0.00 0.00
Sorts: 0.29 0.00
Logons: 0.00 0.00
Executes: 30,980.41 28.56
Transactions: 1,084.65
 
% Blocks changed per Read: 25.93 Recursive Call %: 6.54
Rollback per transaction %: 0.00 Rows per Sort: 126.76
 
Instance Efficiency Percentages (Target 100%)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Buffer Nowait %: 99.98 Redo NoWait %: 100.00
Buffer Hit %: 99.99 In-memory Sort %: 100.00
Library Hit %: 100.02 Soft Parse %: 100.00
Execute to Parse %: 89.47 Latch Hit %: 98.18
Parse CPU to Parse Elapsd %: 83.70 % Non-Parse CPU: 98.47
 
Shared Pool Statistics Begin End
------ ------
Memory Usage %: 42.95 43.16
% SQL with executions>1: 80.91 84.42
% Memory for SQL w/exec>1: 81.85 86.25
 
Top 5 Timed Events
~~~~~~~~~~~~~~~~~~ %
Total
Event Waits Time (s)
Ela Time
-------------------------------------------- ------------ -----------
--------
log file sync 710,816 2,601
24.30
CPU time 2,569
24.00
free buffer waits 3,743 2,525
23.58
latch free 90,584 1,056
9.86
write complete waits 981 749
7.00
-------------------------------------------------------------
 
 
 
CPU Elapsd
Buffer Gets Executions Gets per Exec %Total Time (s) Time (s)
Hash Value
--------------- ------------ -------------- ------ -------- ---------
---------- 9,022,249 2,182,384 4.1 13.6 272.41
527.78 931376387
Module: lisrvr@sut93 (TNS V1-V3)
select entity_cre_flg, del_flg, sol_id, acct_prefix, acct_num, b
acid, foracid, acct_name, acct_short_name, cust_id, emp_id, gl_s
ub_head_code, acct_ownership, schm_code, TO_CHAR(dr_bal_lim), ac
ct_rpt_code, frez_code, frez_reason_code, TO_CHAR(acct_opn_date,
'DD-MM-YYYY HH24:MI:SS'), acct_cls_flg, TO_CHAR(acct_cls_date,'D
 
7,753,648 708,188 10.9 11.7 199.02 1427.49
327885819
Module: lisrvr@sut93 (TNS V1-V3)
insert into TBA_DAILY_TRAN_DETAIL_TBL (tran_date,tran_id,part_tr
an_srl_num,del_flg,tran_type,tran_sub_type,part_tran_type,gl_sub
_head_code,acid,value_date,tran_amt,tran_particular,entry_user_i
d,pstd_user_id,vfd_user_id,entry_date,pstd_date,vfd_date,rpt_cod
e,ref_num,instrmnt_type,instrmnt_date,instrmnt_num,instrmnt_alph
 
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