Vivek - When you've got Cary Millsap quoting Steve Adams, well the advice
just doesn't get any better than that. Go with their advice. As I pointed
out, I replied because at that point nobody had posted yet.

Dennis Williams
DBA, 80%OCP, 100% DBA
Lifetouch, Inc.
[EMAIL PROTECTED] 


-----Original Message-----
Sent: Tuesday, September 02, 2003 12:34 PM
To: Multiple recipients of list ORACLE-L


http://www.ixora.com.au/q+a/0008/24162020.htm


Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com

Upcoming events:
- Hotsos Clinic 101 in Sydney
- Hotsos Symposium 2004, March 7-10 Dallas
- Visit www.hotsos.com for schedule details...


-----Original Message-----
DENNIS WILLIAMS
Sent: Tuesday, September 02, 2003 12:04 PM
To: Multiple recipients of list ORACLE-L

Vivek
    Good question. At this point I haven't seen any replies to your
request.
The specific wait points to the log buffer itself as being too small,
not
particularly the redo logs themselves. Your init.ora parameters show
this
buffer as being only 10-meg. I would suggest you increase it. But your
redo
logs are only 10-meg themselves, so you should consider increasing the
size
of the logs while you are at it or you may hit that as the next limit.
Since
the redo logs are continuously written, it is usually recommended that
they
be on a device that is devoted to redo logs.



Dennis Williams 
DBA, 80%OCP, 100% DBA 
Lifetouch, Inc. 
[EMAIL PROTECTED] 

-----Original Message-----
Sent: Tuesday, September 02, 2003 8:39 AM
To: Multiple recipients of list ORACLE-L



At a Benchmark a particular Processing + DML intensive batch Job
(Accounts
Interest Calculation) is experiencing 

"log buffer space" wait .

 

Config :-

On Solaris 9 

Cpu_count = 72

Oracle 9.2

Online Redo logfiles are on a RAID 0+1 Volume (NOT Raw or RAID 1)
Log_buffer
= 10 M

$ sar Command Outpuit %wio only about 6 % for Volume containing the redo
logfiles

Database in NOARCHIVELOG mode

 

Qs. How can we reduce this wait event ? Would RAW / RAID 1 for redo
logfiles
help ?

Qs. Could this be a Bug ?

 

************************************************************************
****
*********************

STATSPACK report for

 

DB Name         DB Id    Instance     Inst Num Release     Cluster Host

------------ ----------- ------------ -------- ----------- -------
------------

BM2           3727568246 bm2                 1 9.2.0.3.0   NO
sleepy

 

            Snap Id     Snap Time      Sessions Curs/Sess Comment

            ------- ------------------ -------- ---------
-------------------

Begin Snap:     240 01-Sep-03 03:09:41       23       1.5

  End Snap:     241 01-Sep-03 04:00:55       24       1.7

   Elapsed:               51.23 (mins)

 

Top 5 Timed Events

~~~~~~~~~~~~~~~~~~                                                     %
Total

Event                                               Waits    Time (s)
Ela
Time

-------------------------------------------- ------------ -----------
--------

log buffer space                                1,817,258     566,516
56.24

latch free                                      2,964,652     334,120
33.17

log file sync                                      55,230      43,488
4.32

buffer busy waits                                  62,839      26,129
2.59

CPU time                                                       22,018
2.19

          -------------------------------------------------------------




Wait Events for DB: BM2  Instance: bm2  Snaps: 240 -241

-> s  - second

-> cs - centisecond -     100th of a second

-> ms - millisecond -    1000th of a second

-> us - microsecond - 1000000th of a second

-> ordered by wait time desc, waits desc (idle events last)

 

                                                                   Avg

                                                     Total Wait   wait
Waits

Event                               Waits   Timeouts   Time (s)   (ms)
/txn

---------------------------- ------------ ---------- ---------- ------
--------

log buffer space                1,817,258        139    566,516    312
54.4

latch free                      2,964,652    892,594    334,120    113
88.8

log file sync                      55,230     21,210     43,488    787
1.7

buffer busy waits                  62,839     10,250     26,129    416
1.9

 

 




Latch Activity for DB: BM2  Instance: bm2  Snaps: 240 -241

 

                                           Pct    Avg   Wait
Pct

                              Get          Get   Slps   Time
NoWait
NoWait

Latch                       Requests      Miss  /Miss    (s)
Requests
Miss

------------------------ -------------- ------ ------ ------
------------
------

post/wait queue                  97,357    4.7    0.4    577
1,871,155
249.5

process allocation                  751    7.2    3.0     10
747
0.5

process group creation            1,502    0.0             0
0

redo allocation              24,482,283   13.5    0.4 ######
0

redo copy                       675,177   99.6    1.1 ######
21,986,833
708.0

 

init.ora Parameters for DB: BM2  Instance: bm2  Snaps: 240 -241

 

                                                                  End
value

Parameter Name                Begin value                       (if
different)

----------------------------- ---------------------------------
--------------

_db_block_lru_latches         128

audit_trail                   FALSE

background_dump_dest          /oracle/ora92-64/rdbms/log/bdump

compatible                    9.2.0.3

control_files                 /lbmdb02/bm2/data02/control_01_bm

core_dump_dest                /oracle/ora92-64/rdbms/log/cdump

cursor_sharing                EXACT

cursor_space_for_time         TRUE

db_block_size                 8192

db_cache_size                 1258291200

db_file_multiblock_read_count 32

db_files                      1500

db_keep_cache_size            117440512

db_name                       bm2

db_writer_processes           16

dml_locks                     10000

enqueue_resources             680000

hash_join_enabled             FALSE

java_pool_size                16777216

large_pool_size               16777216

log_buffer                    10485760

log_checkpoint_interval       0

log_checkpoint_timeout        0

log_checkpoints_to_alert      TRUE

max_dump_file_size            10240

max_rollback_segments         4000

nls_date_format               DD-MM-YYYY

open_cursors                  1000

open_links                    4

optimizer_index_cost_adj      15

optimizer_mode                CHOOSE

os_authent_prefix

parallel_max_servers          0

parallel_min_servers          0

processes                     3500

session_cached_cursors        50

sessions                      3855

shared_pool_reserved_size     52428800

shared_pool_size              536870912

sort_area_retained_size       2048576

sort_area_size                12582912

timed_statistics              TRUE

transaction_auditing          FALSE

undo_management               AUTO

undo_tablespace               TBA_UNDO

user_dump_dest                /oracle/ora92-64/rdbms/log/udump

utl_file_dir                  *

          -------------------------------------------------------------

 

End of Report

 

 

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: DENNIS WILLIAMS
  INET: [EMAIL PROTECTED]

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).


-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Cary Millsap
  INET: [EMAIL PROTECTED]

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: DENNIS WILLIAMS
  INET: [EMAIL PROTECTED]

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).

Reply via email to