RE: log buffer space wait

[Avnish.Rastogi]

I have 
one question regarding these wait times, may be dump. In the following wait 
events what is the unit of measurement for Time, I believe its in seconds as per 
the documentation. If yes then here stats 
are collected for only 51.23 Minutes (Appx 3073 seconds), how come 
Oracle is showing 566,516 seconds wait for log buffer space. I would appreciate 
if someone can explain.
 
Thanks
 
 

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   


  -Original Message-From: VIVEK_SHARMA 
  [mailto:[EMAIL PROTECTED]Sent: Tuesday, September 02, 2003 
  6:39 AMTo: Multiple recipients of list ORACLE-LSubject: 
  log buffer space wait 
  
  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 - 
  100th 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 gr

RE: log buffer space wait

[Jared . Still]

These are cumalitive times for a few hundred processes.

Jared








<[EMAIL PROTECTED]>
Sent by: [EMAIL PROTECTED]
 09/03/2003 10:34 AM
 Please respond to ORACLE-L

        
        To:        Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]>
        cc:        
        Subject:        RE: log buffer space wait


I have one question regarding these wait times, may be dump. In the following wait events what is the unit of measurement for Time, I believe its in seconds as per the documentation. If yes then here stats are collected for only 51.23 Minutes (Appx 3073 seconds), how come Oracle is showing 566,516 seconds wait for log buffer space. I would appreciate if someone can explain.
 
Thanks
 
 
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                                                       
-Original Message-
From: VIVEK_SHARMA [mailto:[EMAIL PROTECTED]
Sent: Tuesday, September 02, 2003 6:39 AM
To: Multiple recipients of list ORACLE-L
Subject: log buffer space wait 

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 - 100th 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 

RE: log buffer space wait

[DENNIS WILLIAMS]

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 IdInstance 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   WaitsTime (s)
Ela
Time

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

log buffer space1,817,258 566,516
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 - 100th 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 space1,817,258139566,516312
54.4

latch free  2,964,652892,594334,120113
88.8

log file sync  55,230 21,210 43,488787
1.7

buffer busy waits  62,839 10,250 26,129416
1.9

 

 




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

 

   PctAvg   Wait
Pct

  Get  Get   Slps   Time
NoWait
NoWait

Latch   Requests  Miss  /Miss(s)
Requests
Miss

 -- -- -- --

--

post/wait queue  97,3574.70.4577
1,871,155
249.5

process allocation  7517.23.0 10
747
0.5

process group creation1,5020.0 0
0

redo allocation  24,4

Re: log buffer space wait

[Jared . Still]

After doing some reading on this, I suspect that your log files are too small.

I don't see any info on log file size in this post, or at least, I can't find it.

A large percentage of log buffer space waits occurr immediately after a 
log switch, so if you're switching logs very frequently, you will get a lot
of these waits.

A 10 meg buffer is actually pretty large. Since IIRC, you can only fill the
log to 1/3 or 1 meg, whichever comes first, there's not a lot of benefit
to making the log buffer larger.

You will find quite a bit of info on this at Steve Adams site, www.ixora.com.au

HTH

Jared







"Tanel Poder" <[EMAIL PROTECTED]>
Sent by: [EMAIL PROTECTED]
 09/02/2003 08:24 AM
 Please respond to ORACLE-L

        
        To:        Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]>
        cc:        
        Subject:        Re: log buffer space wait


Hi!
 
What's the value for _log_simultaneous_copies parameter? You might want to manually increase it, even though it depends on CPU_COUNT when left default.
I personally would increase log_buffer size as well, if you got that many CPUs and concurrent sessions.
 
Tanel.
 
- Original Message - 
From: VIVEK_SHARMA 
To: Multiple recipients of list ORACLE-L 
Sent: Tuesday, September 02, 2003 4:39 PM
Subject: log buffer space wait 

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 - 100th 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 

Re: log buffer space wait

[Tanel Poder]

Hi!
 
What's the value for _log_simultaneous_copies 
parameter? You might want to manually increase it, even though it depends on 
CPU_COUNT when left default.
I personally would increase log_buffer size as 
well, if you got that many CPUs and concurrent sessions.
 
Tanel.
 

  - Original Message - 
  From: 
  VIVEK_SHARMA 
  To: Multiple recipients of list ORACLE-L 
  
  Sent: Tuesday, September 02, 2003 4:39 
  PM
  Subject: log buffer space wait 
  
  
  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 - 
  100th 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  

RE: log buffer space wait

[Cary Millsap]

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 IdInstance 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   WaitsTime (s)
Ela
Time

  -------
----

log buffer space1,817,258 566,516
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 - 100th 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 space1,817,258139566,516312
54.4

latch free  2,964,652892,594334,120113
88.8

log file sync  55,230 21,210 43,488787
1.7

buffer busy waits  62,839 10,250 26,129416
1.9

 

 




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

 

   PctAvg   Wait
Pct

  Get  Get   Slps   Time
NoWait
NoWait

Latch   Requests  Miss  /Miss(s)
Requests
Miss

 -- -- -- --

--

post/wait queue  97,3574.70.4577
1,871,155
249.5

process allocation  7517.23.0 10
747
0.5

process group creation1,5020.0 0
0

redo allocation  24,482,283   13.50.4 ##
0

redo copy   675,177   99.61.1 ##
21,986,833
708.0

 

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

 

  End
value

Parameter NameBegin value   (if
different)

- -
--

_db

RE: log buffer space wait

[DENNIS WILLIAMS]

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 IdInstance 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   WaitsTime (s) Ela
Time

  -------
----

log buffer space1,817,258 566,516
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 - 100th 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 space1,817,258139566,516312
54.4

latch free  2,964,652892,594334,120113
88.8

log file sync  55,230 21,210 43,488787
1.7

buffer busy waits  62,839 10,250 26,129416
1.9

 

 




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

 

   PctAvg   Wait
Pct

  Get  Get   Slps   Time   NoWait
NoWait

Latch   Requests  Miss  /Miss(s) Requests
Miss

 -- -- -- -- 
--

post/wait queue  97,3574.70.45771,871,155
249.5

process allocation  7517.23.0 10  747
0.5

process group creation1,5020.0 00

redo allocation  24,482,283   13.50.4 ##0

redo copy   675,177   99.61.1 ##   21,986,833
708.0

 

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

 

  End value

Parameter NameBegin value   (if
different)

- -
--

_db_block_lru_latches 128

audit_trail   FALSE

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

compatible9.2.0.3

control_files /lbmdb02/bm2/data02/control_01_bm

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

curso

RE: log buffer space wait

[Mladen Gogala]

Title: Message



They 
say that the silence is golden, but I don't think that the rule applies to the 
mailing lists.
 
 
--Mladen GogalaOracle DBA 

  
  -Original Message-From: 
  [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of zhu 
  chaoSent: Tuesday, September 02, 2003 11:29 AMTo: 
  Multiple recipients of list ORACLE-LSubject: Re: log buffer space 
  wait 
 
Note:
This message is for the named person's use only.  It may contain 
confidential, proprietary or legally privileged information.  No 
confidentiality or privilege is waived or lost by any mistransmission.  If 
you receive this message in error, please immediately delete it and all 
copies of it from your system, destroy any hard copies of it and notify the 
sender.  You must not, directly or indirectly, use, disclose, distribute, 
print, or copy any part of this message if you are not the intended 
recipient. Wang Trading 
LLC and any of its subsidiaries each reserve the right to 
monitor all e-mail communications through its networks.  Any views 
expressed in this message are those of the individual sender, except where the 
message states otherwise and the sender is authorized to state them to be the 
views of any such entity.
 
 

Re: log buffer space wait

[zhu chao]

log buffer space wait

[VIVEK_SHARMA]

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 -
100th 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
1

enqueue_resources
68

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

Re: log buffer space

[Jonathan Lewis]

KG,

I got the direct mail much quicker than the
list mail - but I'll just echo the doubt I raised
in the original.

If you use 10046 level 8 to watch for log writer
writes, I would expect you to see writes that
could be of an almost arbitrary size.

Assume a 3MB log buffer - we 'know' that
Oracle triggers on 1MB:  but what if the
system is busy when a write is triggered
and the users are generating lots of work ?

LGWR writes 1MB - and in that time interval
the users fill the other 2MB of the log buffer.
The next write that LGWR does is 2MB.

You could even argue that if the largest write
you regularly see is 2/3 of the log buffer size, 
then the trigger is probably 1/3 of the log buffer
size.


Regards

Jonathan Lewis
http://www.jlcomp.demon.co.uk

Now available One-day tutorials:
  Cost Based Optimisation
  Trouble-shooting and Tuning
  Indexing Strategies

(see http://www.jlcomp.demon.co.uk/tutorial.html )

UK___April 8th
UK___April 22nd

Denmark May 21-23rd

USA_(FL)_May 2nd


Next dates for the 3-day seminar:
(see http://www.jlcomp.demon.co.uk/seminar.html )

UK_(Manchester)_May
USA_(CA, TX)_August


The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html


- Original Message - 
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: 17 March 2003 17:42


> Jonathan:
> 
> I have just sent a mail which has the test statistics.
> I would appreciate your comments on that..
> 
> Alternatively, people who are curious may want to
> test the log writer writing habits using the
> event 10046^8.
> 
> KG
> 
> 
> Best Regards,
> K Gopalakrishnan
> 


-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Jonathan Lewis
  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).

RE: log buffer space

[K Gopalakrishnan]

Jonathan:

I have just sent a mail which has the test statistics.
I would appreciate your comments on that..

Alternatively, people who are curious may want to
test the log writer writing habits using the
event 10046^8.

KG


Best Regards,
K Gopalakrishnan

 


-Original Message-
Lewis
Sent: Monday, March 17, 2003 7:14 AM
To: Multiple recipients of list ORACLE-L



I've just tried a different test, along the following
lines, which seems to confirm that LGWR is
triggered when the buffer is about 1/3 full.

Set log_buffer to an easy number such as 600K.

Create table with one column of a nice large size,
e.g.  varchar2(1000);

Take snapshot of redo size, redo writes, redo wastage
figures from v$sysstat.

Insert N rows into table.


Taks snapshot and find changes.

Vary the number of rows inserted until
M rows does not result in a redo write
M+1 rows results in a redo write.

Check the redo size for M and M+1 rows.

Under both 8.1.7.4 and 9.2.0.2, I found that
log writer seemed to be consistently triggered
at a couple of KB below 1/3 of the log_buffer.

(One oddity that caused me a little hassle with
9.2 at first was that I set the log buffer to 512K,
but the actual log buffer size (per v$sga) was
actually closer to 640K, so the trigger occurred
at 212K when I was expecting it to be 170K.



Regards

Jonathan Lewis
http://www.jlcomp.demon.co.uk

Now available One-day tutorials:
  Cost Based Optimisation
  Trouble-shooting and Tuning
  Indexing Strategies

(see http://www.jlcomp.demon.co.uk/tutorial.html )

UK___April 8th
UK___April 22nd

Denmark May 21-23rd

USA_(FL)_May 2nd


Next dates for the 3-day seminar:
(see http://www.jlcomp.demon.co.uk/seminar.html )

UK_(Manchester)_May
USA_(CA, TX)_August


The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html


- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: 16 March 2003 13:28


> Arup:
>
> Sorry for the delay ;-)
>
>
> I have not seen this is documented anywhere, other than
> 'Oracle Performance Tuning' OReilly Peter & Mark Gurry
> (page 304) where he claims the log writer writes when
> it is 2/3 full... Here is the Original Text.
>
> 
> Log Buffer
>
> The log buffer contains the information showing the changes that
have
> been made to database buffer blocks. When the log buffer reaches
> one-third full (two-thirds full in Oracle 7.3), a user performs a
commit,
> or a write takes place to the database,..
>
> 
>
> I don't have any Oracle 7.3 database, (for that matter no database
> now as I composing this in Zurich  Airport waiting for a connecting
> flight to Bombay..), So I may not be able to test that. But last
time
> I verified was on an Oracle 8.1 database where the log file writes
> used to be in the order up to 2/3 full.
>
> You can do a simple test to prove this point. You can use oradebug
> to trace the log writer process and do a CTAS of any big table
> (with a big log buffer) and you will be able to see the writes
> and number of blocks written in a single write.
>
> I am surprised , this is not documented anywhere in the Oracle
> Documentation or any of the Oracle University course notes.
>
>
> Best Regards,
> K Gopalakrishnan
>
>


-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Jonathan Lewis
  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: K Gopalakrishnan
  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).

Re: log buffer space

[Jonathan Lewis]

I've just tried a different test, along the following
lines, which seems to confirm that LGWR is
triggered when the buffer is about 1/3 full.

Set log_buffer to an easy number such as 600K.

Create table with one column of a nice large size,
e.g.  varchar2(1000);

Take snapshot of redo size, redo writes, redo wastage
figures from v$sysstat.

Insert N rows into table.


Taks snapshot and find changes.

Vary the number of rows inserted until
M rows does not result in a redo write
M+1 rows results in a redo write.

Check the redo size for M and M+1 rows.

Under both 8.1.7.4 and 9.2.0.2, I found that
log writer seemed to be consistently triggered
at a couple of KB below 1/3 of the log_buffer.

(One oddity that caused me a little hassle with
9.2 at first was that I set the log buffer to 512K,
but the actual log buffer size (per v$sga) was
actually closer to 640K, so the trigger occurred
at 212K when I was expecting it to be 170K.



Regards

Jonathan Lewis
http://www.jlcomp.demon.co.uk

Now available One-day tutorials:
  Cost Based Optimisation
  Trouble-shooting and Tuning
  Indexing Strategies

(see http://www.jlcomp.demon.co.uk/tutorial.html )

UK___April 8th
UK___April 22nd

Denmark May 21-23rd

USA_(FL)_May 2nd


Next dates for the 3-day seminar:
(see http://www.jlcomp.demon.co.uk/seminar.html )

UK_(Manchester)_May
USA_(CA, TX)_August


The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html


- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: 16 March 2003 13:28


> Arup:
>
> Sorry for the delay ;-)
>
>
> I have not seen this is documented anywhere, other than
> 'Oracle Performance Tuning' OReilly Peter & Mark Gurry
> (page 304) where he claims the log writer writes when
> it is 2/3 full... Here is the Original Text.
>
> 
> Log Buffer
>
> The log buffer contains the information showing the changes that
have
> been made to database buffer blocks. When the log buffer reaches
> one-third full (two-thirds full in Oracle 7.3), a user performs a
commit,
> or a write takes place to the database,..
>
> 
>
> I don't have any Oracle 7.3 database, (for that matter no database
> now as I composing this in Zurich  Airport waiting for a connecting
> flight to Bombay..), So I may not be able to test that. But last
time
> I verified was on an Oracle 8.1 database where the log file writes
> used to be in the order up to 2/3 full.
>
> You can do a simple test to prove this point. You can use oradebug
> to trace the log writer process and do a CTAS of any big table
> (with a big log buffer) and you will be able to see the writes
> and number of blocks written in a single write.
>
> I am surprised , this is not documented anywhere in the Oracle
> Documentation or any of the Oracle University course notes.
>
>
> Best Regards,
> K Gopalakrishnan
>
>


-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Jonathan Lewis
  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).

RE: log buffer space

[K Gopalakrishnan]

Arup:

Sorry for the delay ;-)


I have not seen this is documented anywhere, other than
'Oracle Performance Tuning' OReilly Peter & Mark Gurry
(page 304) where he claims the log writer writes when
it is 2/3 full... Here is the Original Text.


Log Buffer

The log buffer contains the information showing the changes that have
been made to database buffer blocks. When the log buffer reaches
one-third full (two-thirds full in Oracle 7.3), a user performs a commit,
or a write takes place to the database,..



I don't have any Oracle 7.3 database, (for that matter no database
now as I composing this in Zurich  Airport waiting for a connecting
flight to Bombay..), So I may not be able to test that. But last time
I verified was on an Oracle 8.1 database where the log file writes
used to be in the order up to 2/3 full.

You can do a simple test to prove this point. You can use oradebug
to trace the log writer process and do a CTAS of any big table
(with a big log buffer) and you will be able to see the writes
and number of blocks written in a single write.

I am surprised , this is not documented anywhere in the Oracle
Documentation or any of the Oracle University course notes.


Best Regards,
K Gopalakrishnan




-Original Message-
Sent: Friday, March 14, 2003 11:04 AM
To: Multiple recipients of list ORACLE-L


Dennis,

The 1MB condition was in 8i as well, at least in 8.1.7, as I mentioned in my
original post.

I was always under impresssion that the flush is triggered by the buffer
being 1/3rd full; but KG mentioned it was 2/3rd, not 1/3rd and I was
wondering where he got that information from and if it's documented. It
true, that will certainly invalidate most of the what the fine manuals and
Oracle Support analysts have said.

Any ideas, anybody?

Arup

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 11:18 AM


> Add one more condition:
>New in Oracle 9i, it will write when 1 meg is reached, so the 1/3
> criteria is never reached if you use a big buffer.
>
> Dennis Williams
> DBA, 40%OCP, 100% DBA
> Lifetouch, Inc.
> [EMAIL PROTECTED]
>
>
> -Original Message-
> Sent: Friday, March 14, 2003 8:59 AM
> To: Multiple recipients of list ORACLE-L
>
>
> KG,
>
> Thanks for the response. Just for my curiosity, is it documented somewhere
> that the log buffer if flushed when 2/3rd full? From the Manual
> /server.920/a96524/c09procs.htm#3158 (please check the URL in OTN, the
first
> part is not complete), here is an excerpt
>
> 
> LGWR writes one contiguous portion of the buffer to disk. LGWR writes:
>   a.. A commit record when a user process commits a transaction
>   b.. Redo log buffers
> a.. Every three seconds
> b.. When the redo log buffer is one-third full
> c.. When a DBWn process writes modified buffers to disk, if necessary
>
> 
>
> At least this was the behavior I tested in 8.1.7; although I have not
tested
> in 9i. This has also been stated by several Oracle Support Analysts.
>
> Thanks.
>
> Arup Nanda
>
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, March 14, 2003 7:32 AM
>
>
> > Arup:
> >
> > 
> > The second condition is not quite true. It is 2/3 full in the current
> > versions.
> > 
> >
> > It is very easy to test with the event 10046^8.
> >
> > KG
> >
> >
> > --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > > AK,
> > >
> > > If the log buffer is at least 4MB, then increasing it will not help,
> > > rather it may hurt. The log buffer is flushed when any of the the
> > > follwoing occur
> > > (i) 1 MB is filled up
> > > (2) 1/3rd is filled up
> > > (3) every 3 seconds
> > > (4) when a checkpoint occurs
> > > (5) when a commit occurs.
> > >
> > > Therefore, see if any of these could be the problem. It's easy to
> > > check #s 4 and 3.
> > >
> > > As Kirti suggested, the problem could be due to the redo logs being
> > > on a busy disk, or even a slow one.
> > >
> > > HTH.
> > >
> > > Arup
> > >   - Original Message -
> > >   From: Deshpande, Kirti
> > >   To: Multiple recipients of list ORACLE-L
> > >   Sent: Thursday, March 13, 2003 8:13 PM
> > >   Subject: RE: log buffer space
> > >
> > >
> > >   Increasing log_buffer size is an option, if it is really small.
> > >   I would also check if the redo logs are on a busy disk. If so, try
> > > moving those (or oth

Re: log buffer space

[Mogens Nørgaard]

It's a fantastic ratio :-).

Anjo Kolk wrote:

1 log switch per minute ;-)

AK wrote:
 

log buffer is 320 K and log files are 30M approx. there are about 50 log
switch /hr .
-ak

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 9:29 AM
   

AK,

Could you provide the redo log sizes and the log_buffers parameters,
 

please.
   

Also let us know the log switch frequency, too.

Thanks.

Arup

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 11:14 AM
 

Do you guys think , adding more log file can help ? I think it should
   

not
   

,
 

cuz any way logwriter is going to write in one datafile at a time ,
   

correct
 

?

-ak

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 4:32 AM
   

Arup:


The second condition is not quite true. It is 2/3 full in the current
versions.

It is very easy to test with the event 10046^8.

KG

--- Arup Nanda <[EMAIL PROTECTED]> wrote:
 

AK,

If the log buffer is at least 4MB, then increasing it will not help,
rather it may hurt. The log buffer is flushed when any of the the
follwoing occur
(i) 1 MB is filled up
(2) 1/3rd is filled up
(3) every 3 seconds
(4) when a checkpoint occurs
(5) when a commit occurs.
Therefore, see if any of these could be the problem. It's easy to
check #s 4 and 3.
As Kirti suggested, the problem could be due to the redo logs being
on a busy disk, or even a slow one.
HTH.

Arup
 - Original Message -
 From: Deshpande, Kirti
 To: Multiple recipients of list ORACLE-L
 Sent: Thursday, March 13, 2003 8:13 PM
 Subject: RE: log buffer space
 Increasing log_buffer size is an option, if it is really small.
 I would also check if the redo logs are on a busy disk. If so, try
moving those (or other busy data files on the same disk) to other
not-so-busy disks.
 - Kirti
   

=
Have a nice day !!

Best Regards,
K Gopalakrishnan,
Bangalore, INDIA.
--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: K Gopalakrishnan
 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: AK
 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: Arup Nanda
 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: AK
 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: =?ISO-8859-1?Q?Mogens_N=F8rgaard?=
 INET: [EM

RE: log buffer space

[Rajesh Dayal]

Dear AK,

So far we don't know your log buffer size. 
Can we have a glimpse of this parameter, log_buffer ?

Rajesh


-Original Message-
Sent: Friday, March 14, 2003 8:14 PM
To: Multiple recipients of list ORACLE-L

Do you guys think , adding more log file can help ? I think it should not ,
cuz any way logwriter is going to write in one datafile at a time , correct
?

-ak


- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 4:32 AM


> Arup:
>
> 
> The second condition is not quite true. It is 2/3 full in the current
> versions.
> 
>
> It is very easy to test with the event 10046^8.
>
> KG
>
>
> --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > AK,
> >
> > If the log buffer is at least 4MB, then increasing it will not help,
> > rather it may hurt. The log buffer is flushed when any of the the
> > follwoing occur
> > (i) 1 MB is filled up
> > (2) 1/3rd is filled up
> > (3) every 3 seconds
> > (4) when a checkpoint occurs
> > (5) when a commit occurs.
> >
> > Therefore, see if any of these could be the problem. It's easy to
> > check #s 4 and 3.
> >
> > As Kirti suggested, the problem could be due to the redo logs being
> > on a busy disk, or even a slow one.
> >
> > HTH.
> >
> > Arup
> >   - Original Message -
> >   From: Deshpande, Kirti
> >   To: Multiple recipients of list ORACLE-L
> >   Sent: Thursday, March 13, 2003 8:13 PM
> >   Subject: RE: log buffer space
> >
> >
> >   Increasing log_buffer size is an option, if it is really small.
> >   I would also check if the redo logs are on a busy disk. If so, try
> > moving those (or other busy data files on the same disk) to other
> > not-so-busy disks.
> >
> >   - Kirti
>
>
> =
> Have a nice day !!
> 
> Best Regards,
> K Gopalakrishnan,
> Bangalore, INDIA.
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: K Gopalakrishnan
>   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: AK
  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: Rajesh Dayal
  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).

Re: log buffer space

[Anjo Kolk]

1 log switch per minute ;-)

AK wrote:
> 
> log buffer is 320 K and log files are 30M approx. there are about 50 log
> switch /hr .
> 
> -ak
> 
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, March 14, 2003 9:29 AM
> 
> > AK,
> >
> > Could you provide the redo log sizes and the log_buffers parameters,
> please.
> > Also let us know the log switch frequency, too.
> >
> > Thanks.
> >
> > Arup
> >
> > - Original Message -
> > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> > Sent: Friday, March 14, 2003 11:14 AM
> >
> >
> > > Do you guys think , adding more log file can help ? I think it should
> not
> > ,
> > > cuz any way logwriter is going to write in one datafile at a time ,
> > correct
> > > ?
> > >
> > > -ak
> > >
> > >
> > > - Original Message -
> > > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> > > Sent: Friday, March 14, 2003 4:32 AM
> > >
> > >
> > > > Arup:
> > > >
> > > > 
> > > > The second condition is not quite true. It is 2/3 full in the current
> > > > versions.
> > > > 
> > > >
> > > > It is very easy to test with the event 10046^8.
> > > >
> > > > KG
> > > >
> > > >
> > > > --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > > > > AK,
> > > > >
> > > > > If the log buffer is at least 4MB, then increasing it will not help,
> > > > > rather it may hurt. The log buffer is flushed when any of the the
> > > > > follwoing occur
> > > > > (i) 1 MB is filled up
> > > > > (2) 1/3rd is filled up
> > > > > (3) every 3 seconds
> > > > > (4) when a checkpoint occurs
> > > > > (5) when a commit occurs.
> > > > >
> > > > > Therefore, see if any of these could be the problem. It's easy to
> > > > > check #s 4 and 3.
> > > > >
> > > > > As Kirti suggested, the problem could be due to the redo logs being
> > > > > on a busy disk, or even a slow one.
> > > > >
> > > > > HTH.
> > > > >
> > > > > Arup
> > > > >   - Original Message -
> > > > >   From: Deshpande, Kirti
> > > > >   To: Multiple recipients of list ORACLE-L
> > > > >   Sent: Thursday, March 13, 2003 8:13 PM
> > > > >   Subject: RE: log buffer space
> > > > >
> > > > >
> > > > >   Increasing log_buffer size is an option, if it is really small.
> > > > >   I would also check if the redo logs are on a busy disk. If so, try
> > > > > moving those (or other busy data files on the same disk) to other
> > > > > not-so-busy disks.
> > > > >
> > > > >   - Kirti
> > > >
> > > >
> > > > =
> > > > Have a nice day !!
> > > > 
> > > > Best Regards,
> > > > K Gopalakrishnan,
> > > > Bangalore, INDIA.
> > > > --
> > > > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > > > --
> > > > Author: K Gopalakrishnan
> > > >   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: AK
> > >   INET: [EMAIL PROTECTED]
> > >
> > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com
> > > Sa

Re: log buffer space

[Darrell Landrum]

I'm sorry, I've missed whether this is a production database in archive log mode or 
not.  If it is, log switches twice per hour may be too few.  You should find out what 
your data loss tolerance is for this instance and adjust your redo log setup to 
accomodate that.  I agree, 50 per hour is a bit much, but there are databases where 30 
minutes of data lost could be quite hurtful.


>>> [EMAIL PROTECTED] 03/14/03 05:29PM >>>
Well, there lies your problem. I suggest you do the following in this order
of priority and see if they resolved the problem.

(1) Log buffer of 320K is definitely small. Make it 4 MB (or at least 3MB)
if you have enough memory.
(2) Your log switching is 50 per hour?!! That's a little too much. Are you
sure it's that high? If so, you need to bring it down to about 2 per hour.
If 50/hr is your average rate of switch, then you need to size the logfiles
at least 25 times current size to achieve the 2 per hour rate. Make your
logs 500M each, again if you have enough disk space.
(3) If possible, try to move the redo logs to non-RAID disks, preferably
local (direct attached).

HTH.

Arup Nanda

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 5:34 PM


> log buffer is 320 K and log files are 30M approx. there are about 50 log
> switch /hr .
>
> -ak
>
>
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, March 14, 2003 9:29 AM
>
>
> > AK,
> >
> > Could you provide the redo log sizes and the log_buffers parameters,
> please.
> > Also let us know the log switch frequency, too.
> >
> > Thanks.
> >
> > Arup
> >
> > - Original Message -
> > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> > Sent: Friday, March 14, 2003 11:14 AM
> >
> >
> > > Do you guys think , adding more log file can help ? I think it should
> not
> > ,
> > > cuz any way logwriter is going to write in one datafile at a time ,
> > correct
> > > ?
> > >
> > > -ak
> > >
> > >
> > > - Original Message -
> > > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> > > Sent: Friday, March 14, 2003 4:32 AM
> > >
> > >
> > > > Arup:
> > > >
> > > > 
> > > > The second condition is not quite true. It is 2/3 full in the
current
> > > > versions.
> > > > 
> > > >
> > > > It is very easy to test with the event 10046^8.
> > > >
> > > > KG
> > > >
> > > >
> > > > --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > > > > AK,
> > > > >
> > > > > If the log buffer is at least 4MB, then increasing it will not
help,
> > > > > rather it may hurt. The log buffer is flushed when any of the the
> > > > > follwoing occur
> > > > > (i) 1 MB is filled up
> > > > > (2) 1/3rd is filled up
> > > > > (3) every 3 seconds
> > > > > (4) when a checkpoint occurs
> > > > > (5) when a commit occurs.
> > > > >
> > > > > Therefore, see if any of these could be the problem. It's easy to
> > > > > check #s 4 and 3.
> > > > >
> > > > > As Kirti suggested, the problem could be due to the redo logs
being
> > > > > on a busy disk, or even a slow one.
> > > > >
> > > > > HTH.
> > > > >
> > > > > Arup
> > > > >   - Original Message -
> > > > >   From: Deshpande, Kirti
> > > > >   To: Multiple recipients of list ORACLE-L
> > > > >   Sent: Thursday, March 13, 2003 8:13 PM
> > > > >   Subject: RE: log buffer space
> > > > >
> > > > >
> > > > >   Increasing log_buffer size is an option, if it is really small.
> > > > >   I would also check if the redo logs are on a busy disk. If so,
try
> > > > > moving those (or other busy data files on the same disk) to other
> > > > > not-so-busy disks.
> > > > >
> > > > >   - Kirti
> > > >
> > > >
> > > > =
> > > > Have a nice day !!
> > > > 
> > > > Best Regards,
> > > > K Gopalakrishnan,
> > 

Re: log buffer space

[Mogens Nørgaard]

50 log switches per hour is a LOT. Get it down to a handful or so by increasing
the size of the redo logs with a factor 10 or so. Redo buffer sounds a bit
small, and going to 1M in size might help a bit, although there's no guarantee
for it.

Mogens

AK wrote:

  log buffer is 320 K and log files are 30M approx. there are about 50 log
switch /hr .

-ak


- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 9:29 AM


  
  
AK,

Could you provide the redo log sizes and the log_buffers parameters,

  
  please.
  
  
Also let us know the log switch frequency, too.

Thanks.

Arup

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 11:14 AM




  Do you guys think , adding more log file can help ? I think it should
  

  
  not
  
  
,


  cuz any way logwriter is going to write in one datafile at a time ,
  

correct


  ?

-ak


- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 4:32 AM


  
  
Arup:


The second condition is not quite true. It is 2/3 full in the current
versions.


It is very easy to test with the event 10046^8.

KG


--- Arup Nanda <[EMAIL PROTECTED]> wrote:


  AK,

If the log buffer is at least 4MB, then increasing it will not help,
rather it may hurt. The log buffer is flushed when any of the the
follwoing occur
(i) 1 MB is filled up
(2) 1/3rd is filled up
(3) every 3 seconds
(4) when a checkpoint occurs
(5) when a commit occurs.

Therefore, see if any of these could be the problem. It's easy to
check #s 4 and 3.

As Kirti suggested, the problem could be due to the redo logs being
on a busy disk, or even a slow one.

HTH.

Arup
  - Original Message -
  From: Deshpande, Kirti
  To: Multiple recipients of list ORACLE-L
  Sent: Thursday, March 13, 2003 8:13 PM
  Subject: RE: log buffer space


  Increasing log_buffer size is an option, if it is really small.
  I would also check if the redo logs are on a busy disk. If so, try
moving those (or other busy data files on the same disk) to other
not-so-busy disks.

  - Kirti
  


=
Have a nice day !!

Best Regards,
K Gopalakrishnan,
Bangalore, INDIA.
--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: K Gopalakrishnan
  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: AK
  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: Arup Nanda
  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).



  

Re: log buffer space

[Arup Nanda]

Well, there lies your problem. I suggest you do the following in this order
of priority and see if they resolved the problem.

(1) Log buffer of 320K is definitely small. Make it 4 MB (or at least 3MB)
if you have enough memory.
(2) Your log switching is 50 per hour?!! That's a little too much. Are you
sure it's that high? If so, you need to bring it down to about 2 per hour.
If 50/hr is your average rate of switch, then you need to size the logfiles
at least 25 times current size to achieve the 2 per hour rate. Make your
logs 500M each, again if you have enough disk space.
(3) If possible, try to move the redo logs to non-RAID disks, preferably
local (direct attached).

HTH.

Arup Nanda

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 5:34 PM


> log buffer is 320 K and log files are 30M approx. there are about 50 log
> switch /hr .
>
> -ak
>
>
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, March 14, 2003 9:29 AM
>
>
> > AK,
> >
> > Could you provide the redo log sizes and the log_buffers parameters,
> please.
> > Also let us know the log switch frequency, too.
> >
> > Thanks.
> >
> > Arup
> >
> > - Original Message -
> > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> > Sent: Friday, March 14, 2003 11:14 AM
> >
> >
> > > Do you guys think , adding more log file can help ? I think it should
> not
> > ,
> > > cuz any way logwriter is going to write in one datafile at a time ,
> > correct
> > > ?
> > >
> > > -ak
> > >
> > >
> > > - Original Message -
> > > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> > > Sent: Friday, March 14, 2003 4:32 AM
> > >
> > >
> > > > Arup:
> > > >
> > > > 
> > > > The second condition is not quite true. It is 2/3 full in the
current
> > > > versions.
> > > > 
> > > >
> > > > It is very easy to test with the event 10046^8.
> > > >
> > > > KG
> > > >
> > > >
> > > > --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > > > > AK,
> > > > >
> > > > > If the log buffer is at least 4MB, then increasing it will not
help,
> > > > > rather it may hurt. The log buffer is flushed when any of the the
> > > > > follwoing occur
> > > > > (i) 1 MB is filled up
> > > > > (2) 1/3rd is filled up
> > > > > (3) every 3 seconds
> > > > > (4) when a checkpoint occurs
> > > > > (5) when a commit occurs.
> > > > >
> > > > > Therefore, see if any of these could be the problem. It's easy to
> > > > > check #s 4 and 3.
> > > > >
> > > > > As Kirti suggested, the problem could be due to the redo logs
being
> > > > > on a busy disk, or even a slow one.
> > > > >
> > > > > HTH.
> > > > >
> > > > > Arup
> > > > >   - Original Message -
> > > > >   From: Deshpande, Kirti
> > > > >   To: Multiple recipients of list ORACLE-L
> > > > >   Sent: Thursday, March 13, 2003 8:13 PM
> > > > >   Subject: RE: log buffer space
> > > > >
> > > > >
> > > > >   Increasing log_buffer size is an option, if it is really small.
> > > > >   I would also check if the redo logs are on a busy disk. If so,
try
> > > > > moving those (or other busy data files on the same disk) to other
> > > > > not-so-busy disks.
> > > > >
> > > > >   - Kirti
> > > >
> > > >
> > > > =
> > > > Have a nice day !!
> > > > 
> > > > Best Regards,
> > > > K Gopalakrishnan,
> > > > Bangalore, INDIA.
> > > > --
> > > > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > > > --
> > > > Author: K Gopalakrishnan
> > > >   INET: [EMAIL PROTECTED]
> > > >
> > > > Fat City Network Services-- 858-538-5051 http://www.fatcity.com
> > > > San Diego, California-- Mailing list and web hosting
services
> > >
> -

Re: log buffer space

[AK]

log buffer is 320 K and log files are 30M approx. there are about 50 log
switch /hr .

-ak


- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 9:29 AM


> AK,
>
> Could you provide the redo log sizes and the log_buffers parameters,
please.
> Also let us know the log switch frequency, too.
>
> Thanks.
>
> Arup
>
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, March 14, 2003 11:14 AM
>
>
> > Do you guys think , adding more log file can help ? I think it should
not
> ,
> > cuz any way logwriter is going to write in one datafile at a time ,
> correct
> > ?
> >
> > -ak
> >
> >
> > - Original Message -
> > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> > Sent: Friday, March 14, 2003 4:32 AM
> >
> >
> > > Arup:
> > >
> > > 
> > > The second condition is not quite true. It is 2/3 full in the current
> > > versions.
> > > 
> > >
> > > It is very easy to test with the event 10046^8.
> > >
> > > KG
> > >
> > >
> > > --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > > > AK,
> > > >
> > > > If the log buffer is at least 4MB, then increasing it will not help,
> > > > rather it may hurt. The log buffer is flushed when any of the the
> > > > follwoing occur
> > > > (i) 1 MB is filled up
> > > > (2) 1/3rd is filled up
> > > > (3) every 3 seconds
> > > > (4) when a checkpoint occurs
> > > > (5) when a commit occurs.
> > > >
> > > > Therefore, see if any of these could be the problem. It's easy to
> > > > check #s 4 and 3.
> > > >
> > > > As Kirti suggested, the problem could be due to the redo logs being
> > > > on a busy disk, or even a slow one.
> > > >
> > > > HTH.
> > > >
> > > > Arup
> > > >   - Original Message -
> > > >   From: Deshpande, Kirti
> > > >   To: Multiple recipients of list ORACLE-L
> > > >   Sent: Thursday, March 13, 2003 8:13 PM
> > > >   Subject: RE: log buffer space
> > > >
> > > >
> > > >   Increasing log_buffer size is an option, if it is really small.
> > > >   I would also check if the redo logs are on a busy disk. If so, try
> > > > moving those (or other busy data files on the same disk) to other
> > > > not-so-busy disks.
> > > >
> > > >   - Kirti
> > >
> > >
> > > =
> > > Have a nice day !!
> > > 
> > > Best Regards,
> > > K Gopalakrishnan,
> > > Bangalore, INDIA.
> > > --
> > > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > > --
> > > Author: K Gopalakrishnan
> > >   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: AK
> >   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
> --
> 

RE: log buffer space

[Rachel Carmichael]

I remember seeing documentation on it for 8i as well.


--- Pete Sharman <[EMAIL PROTECTED]> wrote:
> Really?  I thought that condition was there pre-9i as well.  Maybe
> I'm
> mistaken.
> 
> Pete
> "Controlling developers is like herding cats."
> Kevin Loney, Oracle DBA Handbook
> "Oh no, it's not.  It's much harder than that!"
> Bruce Pihlamae, long-term Oracle DBA
>  
> 
> 
> -Original Message-
> WILLIAMS
> Sent: Friday, March 14, 2003 8:19 AM
> To: Multiple recipients of list ORACLE-L
> 
> 
> Add one more condition: 
>New in Oracle 9i, it will write when 1 meg is reached, so the 1/3
> criteria is never reached if you use a big buffer.
> 
> Dennis Williams
> DBA, 40%OCP, 100% DBA
> Lifetouch, Inc.
> [EMAIL PROTECTED] 
> 
> 
> -Original Message-
> Sent: Friday, March 14, 2003 8:59 AM
> To: Multiple recipients of list ORACLE-L
> 
> 
> KG,
> 
> Thanks for the response. Just for my curiosity, is it documented
> somewhere that the log buffer if flushed when 2/3rd full? From the
> Manual /server.920/a96524/c09procs.htm#3158 (please check the URL in
> OTN, the first part is not complete), here is an excerpt
> 
> 
> LGWR writes one contiguous portion of the buffer to disk. LGWR
> writes:
>   a.. A commit record when a user process commits a transaction
>   b.. Redo log buffers
> a.. Every three seconds
> b.. When the redo log buffer is one-third full
> c.. When a DBWn process writes modified buffers to disk, if
> necessary
> 
> 
> 
> At least this was the behavior I tested in 8.1.7; although I have not
> tested in 9i. This has also been stated by several Oracle Support
> Analysts.
> 
> Thanks.
> 
> Arup Nanda
> 
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, March 14, 2003 7:32 AM
> 
> 
> > Arup:
> >
> > 
> > The second condition is not quite true. It is 2/3 full in the
> current 
> > versions. 
> >
> > It is very easy to test with the event 10046^8.
> >
> > KG
> >
> >
> > --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > > AK,
> > >
> > > If the log buffer is at least 4MB, then increasing it will not
> help,
> 
> > > rather it may hurt. The log buffer is flushed when any of the the
> 
> > > follwoing occur
> > > (i) 1 MB is filled up
> > > (2) 1/3rd is filled up
> > > (3) every 3 seconds
> > > (4) when a checkpoint occurs
> > > (5) when a commit occurs.
> > >
> > > Therefore, see if any of these could be the problem. It's easy to
> 
> > > check #s 4 and 3.
> > >
> > > As Kirti suggested, the problem could be due to the redo logs
> being 
> > > on a busy disk, or even a slow one.
> > >
> > > HTH.
> > >
> > > Arup
> > >   - Original Message -
> > >   From: Deshpande, Kirti
> > >   To: Multiple recipients of list ORACLE-L
> > >   Sent: Thursday, March 13, 2003 8:13 PM
> > >   Subject: RE: log buffer space
> > >
> > >
> > >   Increasing log_buffer size is an option, if it is really small.
> > >   I would also check if the redo logs are on a busy disk. If so,
> try
> 
> > > moving those (or other busy data files on the same disk) to other
> 
> > > not-so-busy disks.
> > >
> > >   - Kirti
> >
> >
> > =
> > Have a nice day !!
> > 
> > Best Regards,
> > K Gopalakrishnan,
> > Bangalore, INDIA.
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > --
> > Author: K Gopalakrishnan
> >   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: Arup Nanda
>   INET: [EMAIL PROTECT

RE: log buffer space

[DENNIS WILLIAMS]

Arup
   I have a busy day, so the only resource I can quote without research is
the Oracle Education Oracle9i Database Performance Tuning Student Guide.
Lesson 5-3 reads: "When the redo log buffer is one-third full". Hope that
answers your question.

Dennis Williams
DBA, 40%OCP, 100% DBA
Lifetouch, Inc.
[EMAIL PROTECTED] 


-Original Message-
Sent: Friday, March 14, 2003 1:04 PM
To: Multiple recipients of list ORACLE-L


Dennis,

The 1MB condition was in 8i as well, at least in 8.1.7, as I mentioned in my
original post.

I was always under impresssion that the flush is triggered by the buffer
being 1/3rd full; but KG mentioned it was 2/3rd, not 1/3rd and I was
wondering where he got that information from and if it's documented. It
true, that will certainly invalidate most of the what the fine manuals and
Oracle Support analysts have said.

Any ideas, anybody?

Arup

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 11:18 AM


> Add one more condition:
>New in Oracle 9i, it will write when 1 meg is reached, so the 1/3
> criteria is never reached if you use a big buffer.
>
> Dennis Williams
> DBA, 40%OCP, 100% DBA
> Lifetouch, Inc.
> [EMAIL PROTECTED]
>
>
> -Original Message-
> Sent: Friday, March 14, 2003 8:59 AM
> To: Multiple recipients of list ORACLE-L
>
>
> KG,
>
> Thanks for the response. Just for my curiosity, is it documented somewhere
> that the log buffer if flushed when 2/3rd full? From the Manual
> /server.920/a96524/c09procs.htm#3158 (please check the URL in OTN, the
first
> part is not complete), here is an excerpt
>
> 
> LGWR writes one contiguous portion of the buffer to disk. LGWR writes:
>   a.. A commit record when a user process commits a transaction
>   b.. Redo log buffers
> a.. Every three seconds
> b.. When the redo log buffer is one-third full
> c.. When a DBWn process writes modified buffers to disk, if necessary
>
> 
>
> At least this was the behavior I tested in 8.1.7; although I have not
tested
> in 9i. This has also been stated by several Oracle Support Analysts.
>
> Thanks.
>
> Arup Nanda
>
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, March 14, 2003 7:32 AM
>
>
> > Arup:
> >
> > 
> > The second condition is not quite true. It is 2/3 full in the current
> > versions.
> > 
> >
> > It is very easy to test with the event 10046^8.
> >
> > KG
> >
> >
> > --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > > AK,
> > >
> > > If the log buffer is at least 4MB, then increasing it will not help,
> > > rather it may hurt. The log buffer is flushed when any of the the
> > > follwoing occur
> > > (i) 1 MB is filled up
> > > (2) 1/3rd is filled up
> > > (3) every 3 seconds
> > > (4) when a checkpoint occurs
> > > (5) when a commit occurs.
> > >
> > > Therefore, see if any of these could be the problem. It's easy to
> > > check #s 4 and 3.
> > >
> > > As Kirti suggested, the problem could be due to the redo logs being
> > > on a busy disk, or even a slow one.
> > >
> > > HTH.
> > >
> > > Arup
> > >   - Original Message -
> > >   From: Deshpande, Kirti
> > >   To: Multiple recipients of list ORACLE-L
> > >   Sent: Thursday, March 13, 2003 8:13 PM
> > >   Subject: RE: log buffer space
> > >
> > >
> > >   Increasing log_buffer size is an option, if it is really small.
> > >   I would also check if the redo logs are on a busy disk. If so, try
> > > moving those (or other busy data files on the same disk) to other
> > > not-so-busy disks.
> > >
> > >   - Kirti
> >
> >
> > =
> > Have a nice day !!
> > 
> > Best Regards,
> > K Gopalakrishnan,
> > Bangalore, INDIA.
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > --
> > Author: K Gopalakrishnan
> >   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, in

RE: log buffer space

[Pete Sharman]

Maybe finger stutter.  I've never seen it mentioned anywhere except as
1/3.

Pete
"Controlling developers is like herding cats."
Kevin Loney, Oracle DBA Handbook
"Oh no, it's not.  It's much harder than that!"
Bruce Pihlamae, long-term Oracle DBA
 


-Original Message-
Sent: Friday, March 14, 2003 11:04 AM
To: Multiple recipients of list ORACLE-L


Dennis,

The 1MB condition was in 8i as well, at least in 8.1.7, as I mentioned
in my original post.

I was always under impresssion that the flush is triggered by the buffer
being 1/3rd full; but KG mentioned it was 2/3rd, not 1/3rd and I was
wondering where he got that information from and if it's documented. It
true, that will certainly invalidate most of the what the fine manuals
and Oracle Support analysts have said.

Any ideas, anybody?

Arup

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 11:18 AM


> Add one more condition:
>New in Oracle 9i, it will write when 1 meg is reached, so the 1/3 
> criteria is never reached if you use a big buffer.
>
> Dennis Williams
> DBA, 40%OCP, 100% DBA
> Lifetouch, Inc.
> [EMAIL PROTECTED]
>
>
> -Original Message-
> Sent: Friday, March 14, 2003 8:59 AM
> To: Multiple recipients of list ORACLE-L
>
>
> KG,
>
> Thanks for the response. Just for my curiosity, is it documented 
> somewhere that the log buffer if flushed when 2/3rd full? From the 
> Manual /server.920/a96524/c09procs.htm#3158 (please check the URL in 
> OTN, the
first
> part is not complete), here is an excerpt
>
> 
> LGWR writes one contiguous portion of the buffer to disk. LGWR writes:
>   a.. A commit record when a user process commits a transaction
>   b.. Redo log buffers
> a.. Every three seconds
> b.. When the redo log buffer is one-third full
> c.. When a DBWn process writes modified buffers to disk, if 
> necessary
>
> 
>
> At least this was the behavior I tested in 8.1.7; although I have not
tested
> in 9i. This has also been stated by several Oracle Support Analysts.
>
> Thanks.
>
> Arup Nanda
>
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, March 14, 2003 7:32 AM
>
>
> > Arup:
> >
> > 
> > The second condition is not quite true. It is 2/3 full in the 
> > current versions. 
> >
> > It is very easy to test with the event 10046^8.
> >
> > KG
> >
> >
> > --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > > AK,
> > >
> > > If the log buffer is at least 4MB, then increasing it will not 
> > > help, rather it may hurt. The log buffer is flushed when any of 
> > > the the follwoing occur
> > > (i) 1 MB is filled up
> > > (2) 1/3rd is filled up
> > > (3) every 3 seconds
> > > (4) when a checkpoint occurs
> > > (5) when a commit occurs.
> > >
> > > Therefore, see if any of these could be the problem. It's easy to 
> > > check #s 4 and 3.
> > >
> > > As Kirti suggested, the problem could be due to the redo logs 
> > > being on a busy disk, or even a slow one.
> > >
> > > HTH.
> > >
> > > Arup
> > >   - Original Message -
> > >   From: Deshpande, Kirti
> > >   To: Multiple recipients of list ORACLE-L
> > >   Sent: Thursday, March 13, 2003 8:13 PM
> > >   Subject: RE: log buffer space
> > >
> > >
> > >   Increasing log_buffer size is an option, if it is really small.
> > >   I would also check if the redo logs are on a busy disk. If so, 
> > > try moving those (or other busy data files on the same disk) to 
> > > other not-so-busy disks.
> > >
> > >   - Kirti
> >
> >
> > =
> > Have a nice day !!
> > 
> > Best Regards,
> > K Gopalakrishnan,
> > Bangalore, INDIA.
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > --
> > Author: K Gopalakrishnan
> >   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 OR

Re: log buffer space

[Arup Nanda]

Dennis,

The 1MB condition was in 8i as well, at least in 8.1.7, as I mentioned in my
original post.

I was always under impresssion that the flush is triggered by the buffer
being 1/3rd full; but KG mentioned it was 2/3rd, not 1/3rd and I was
wondering where he got that information from and if it's documented. It
true, that will certainly invalidate most of the what the fine manuals and
Oracle Support analysts have said.

Any ideas, anybody?

Arup

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 11:18 AM


> Add one more condition:
>New in Oracle 9i, it will write when 1 meg is reached, so the 1/3
> criteria is never reached if you use a big buffer.
>
> Dennis Williams
> DBA, 40%OCP, 100% DBA
> Lifetouch, Inc.
> [EMAIL PROTECTED]
>
>
> -Original Message-
> Sent: Friday, March 14, 2003 8:59 AM
> To: Multiple recipients of list ORACLE-L
>
>
> KG,
>
> Thanks for the response. Just for my curiosity, is it documented somewhere
> that the log buffer if flushed when 2/3rd full? From the Manual
> /server.920/a96524/c09procs.htm#3158 (please check the URL in OTN, the
first
> part is not complete), here is an excerpt
>
> 
> LGWR writes one contiguous portion of the buffer to disk. LGWR writes:
>   a.. A commit record when a user process commits a transaction
>   b.. Redo log buffers
> a.. Every three seconds
> b.. When the redo log buffer is one-third full
> c.. When a DBWn process writes modified buffers to disk, if necessary
>
> 
>
> At least this was the behavior I tested in 8.1.7; although I have not
tested
> in 9i. This has also been stated by several Oracle Support Analysts.
>
> Thanks.
>
> Arup Nanda
>
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, March 14, 2003 7:32 AM
>
>
> > Arup:
> >
> > 
> > The second condition is not quite true. It is 2/3 full in the current
> > versions.
> > 
> >
> > It is very easy to test with the event 10046^8.
> >
> > KG
> >
> >
> > --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > > AK,
> > >
> > > If the log buffer is at least 4MB, then increasing it will not help,
> > > rather it may hurt. The log buffer is flushed when any of the the
> > > follwoing occur
> > > (i) 1 MB is filled up
> > > (2) 1/3rd is filled up
> > > (3) every 3 seconds
> > > (4) when a checkpoint occurs
> > > (5) when a commit occurs.
> > >
> > > Therefore, see if any of these could be the problem. It's easy to
> > > check #s 4 and 3.
> > >
> > > As Kirti suggested, the problem could be due to the redo logs being
> > > on a busy disk, or even a slow one.
> > >
> > > HTH.
> > >
> > > Arup
> > >   - Original Message -
> > >   From: Deshpande, Kirti
> > >   To: Multiple recipients of list ORACLE-L
> > >   Sent: Thursday, March 13, 2003 8:13 PM
> > >   Subject: RE: log buffer space
> > >
> > >
> > >   Increasing log_buffer size is an option, if it is really small.
> > >   I would also check if the redo logs are on a busy disk. If so, try
> > > moving those (or other busy data files on the same disk) to other
> > > not-so-busy disks.
> > >
> > >   - Kirti
> >
> >
> > =
> > Have a nice day !!
> > 
> > Best Regards,
> > K Gopalakrishnan,
> > Bangalore, INDIA.
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > --
> > Author: K Gopalakrishnan
> >   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: Arup Nanda
>   INET: [EMAIL PROTECTED]
>
> Fat City Network Services-- 858-538-5051 http://www.fatcity.com
> San Diego, California 

RE: log buffer space

[Chris Stephens]

Title: RE: log buffer space





I think this might help...



http://www.ixora.com.au/tips/tuning/log_buffer_size.htm





-Original Message-
From: Deshpande, Kirti [mailto:[EMAIL PROTECTED]] 
Sent: Friday, March 14, 2003 11:19 AM
To: Multiple recipients of list ORACLE-L
Subject: RE: log buffer space


What's the size of your log buffer, and the redo log file? 
Do you see any errors/messages in alert.log file that are related to 'checkpoints' or 'log switching'? 


- Kirti 


-Original Message-
Sent: Friday, March 14, 2003 10:14 AM
To: Multiple recipients of list ORACLE-L



Do you guys think , adding more log file can help ? I think it should not ,
cuz any way logwriter is going to write in one datafile at a time , correct
?


-ak



- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 4:32 AM



> Arup:
>
> 
> The second condition is not quite true. It is 2/3 full in the current
> versions.
> 
>
> It is very easy to test with the event 10046^8.
>
> KG
>
>
> --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > AK,
> >
> > If the log buffer is at least 4MB, then increasing it will not help,
> > rather it may hurt. The log buffer is flushed when any of the the
> > follwoing occur
> > (i) 1 MB is filled up
> > (2) 1/3rd is filled up
> > (3) every 3 seconds
> > (4) when a checkpoint occurs
> > (5) when a commit occurs.
> >
> > Therefore, see if any of these could be the problem. It's easy to
> > check #s 4 and 3.
> >
> > As Kirti suggested, the problem could be due to the redo logs being
> > on a busy disk, or even a slow one.
> >
> > HTH.
> >
> > Arup
> >   - Original Message -
> >   From: Deshpande, Kirti
> >   To: Multiple recipients of list ORACLE-L
> >   Sent: Thursday, March 13, 2003 8:13 PM
> >   Subject: RE: log buffer space
> >
> >
> >   Increasing log_buffer size is an option, if it is really small.
> >   I would also check if the redo logs are on a busy disk. If so, try
> > moving those (or other busy data files on the same disk) to other
> > not-so-busy disks.
> >
> >   - Kirti
>
>


-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Deshpande, Kirti
  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).

RE: log buffer space

[Pete Sharman]

Really?  I thought that condition was there pre-9i as well.  Maybe I'm
mistaken.

Pete
"Controlling developers is like herding cats."
Kevin Loney, Oracle DBA Handbook
"Oh no, it's not.  It's much harder than that!"
Bruce Pihlamae, long-term Oracle DBA
 


-Original Message-
WILLIAMS
Sent: Friday, March 14, 2003 8:19 AM
To: Multiple recipients of list ORACLE-L


Add one more condition: 
   New in Oracle 9i, it will write when 1 meg is reached, so the 1/3
criteria is never reached if you use a big buffer.

Dennis Williams
DBA, 40%OCP, 100% DBA
Lifetouch, Inc.
[EMAIL PROTECTED] 


-Original Message-
Sent: Friday, March 14, 2003 8:59 AM
To: Multiple recipients of list ORACLE-L


KG,

Thanks for the response. Just for my curiosity, is it documented
somewhere that the log buffer if flushed when 2/3rd full? From the
Manual /server.920/a96524/c09procs.htm#3158 (please check the URL in
OTN, the first part is not complete), here is an excerpt


LGWR writes one contiguous portion of the buffer to disk. LGWR writes:
  a.. A commit record when a user process commits a transaction
  b.. Redo log buffers
a.. Every three seconds
b.. When the redo log buffer is one-third full
c.. When a DBWn process writes modified buffers to disk, if
necessary



At least this was the behavior I tested in 8.1.7; although I have not
tested in 9i. This has also been stated by several Oracle Support
Analysts.

Thanks.

Arup Nanda

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 7:32 AM


> Arup:
>
> 
> The second condition is not quite true. It is 2/3 full in the current 
> versions. 
>
> It is very easy to test with the event 10046^8.
>
> KG
>
>
> --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > AK,
> >
> > If the log buffer is at least 4MB, then increasing it will not help,

> > rather it may hurt. The log buffer is flushed when any of the the 
> > follwoing occur
> > (i) 1 MB is filled up
> > (2) 1/3rd is filled up
> > (3) every 3 seconds
> > (4) when a checkpoint occurs
> > (5) when a commit occurs.
> >
> > Therefore, see if any of these could be the problem. It's easy to 
> > check #s 4 and 3.
> >
> > As Kirti suggested, the problem could be due to the redo logs being 
> > on a busy disk, or even a slow one.
> >
> > HTH.
> >
> > Arup
> >   - Original Message -
> >   From: Deshpande, Kirti
> >   To: Multiple recipients of list ORACLE-L
> >   Sent: Thursday, March 13, 2003 8:13 PM
> >   Subject: RE: log buffer space
> >
> >
> >   Increasing log_buffer size is an option, if it is really small.
> >   I would also check if the redo logs are on a busy disk. If so, try

> > moving those (or other busy data files on the same disk) to other 
> > not-so-busy disks.
> >
> >   - Kirti
>
>
> =
> Have a nice day !!
> 
> Best Regards,
> K Gopalakrishnan,
> Bangalore, INDIA.
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: K Gopalakrishnan
>   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: Arup Nanda
  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
-

Re: log buffer space

[Arup Nanda]

AK,

Could you provide the redo log sizes and the log_buffers parameters, please.
Also let us know the log switch frequency, too.

Thanks.

Arup

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 11:14 AM


> Do you guys think , adding more log file can help ? I think it should not
,
> cuz any way logwriter is going to write in one datafile at a time ,
correct
> ?
>
> -ak
>
>
> - Original Message -
> To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
> Sent: Friday, March 14, 2003 4:32 AM
>
>
> > Arup:
> >
> > 
> > The second condition is not quite true. It is 2/3 full in the current
> > versions.
> > 
> >
> > It is very easy to test with the event 10046^8.
> >
> > KG
> >
> >
> > --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > > AK,
> > >
> > > If the log buffer is at least 4MB, then increasing it will not help,
> > > rather it may hurt. The log buffer is flushed when any of the the
> > > follwoing occur
> > > (i) 1 MB is filled up
> > > (2) 1/3rd is filled up
> > > (3) every 3 seconds
> > > (4) when a checkpoint occurs
> > > (5) when a commit occurs.
> > >
> > > Therefore, see if any of these could be the problem. It's easy to
> > > check #s 4 and 3.
> > >
> > > As Kirti suggested, the problem could be due to the redo logs being
> > > on a busy disk, or even a slow one.
> > >
> > > HTH.
> > >
> > > Arup
> > >   - Original Message -
> > >   From: Deshpande, Kirti
> > >   To: Multiple recipients of list ORACLE-L
> > >   Sent: Thursday, March 13, 2003 8:13 PM
> > >   Subject: RE: log buffer space
> > >
> > >
> > >   Increasing log_buffer size is an option, if it is really small.
> > >   I would also check if the redo logs are on a busy disk. If so, try
> > > moving those (or other busy data files on the same disk) to other
> > > not-so-busy disks.
> > >
> > >   - Kirti
> >
> >
> > =
> > Have a nice day !!
> > 
> > Best Regards,
> > K Gopalakrishnan,
> > Bangalore, INDIA.
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > --
> > Author: K Gopalakrishnan
> >   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: AK
>   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: Arup Nanda
  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).

RE: log buffer space

[Cary Millsap]

I think the only ways adding more log files might help is if your app is
waiting on "log file switch (%)" events.


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

Upcoming events:
- Hotsos Clinic 101, Mar 25-27 Oxford
- Hotsos Clinic 101, Apr  8-10 Chicago


-Original Message-
Sent: Friday, March 14, 2003 10:14 AM
To: Multiple recipients of list ORACLE-L

Do you guys think , adding more log file can help ? I think it should not ,
cuz any way logwriter is going to write in one datafile at a time , correct
?

-ak


- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 4:32 AM


> Arup:
>
> 
> The second condition is not quite true. It is 2/3 full in the current
> versions.
> 
>
> It is very easy to test with the event 10046^8.
>
> KG
>
>
> --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > AK,
> >
> > If the log buffer is at least 4MB, then increasing it will not help,
> > rather it may hurt. The log buffer is flushed when any of the the
> > follwoing occur
> > (i) 1 MB is filled up
> > (2) 1/3rd is filled up
> > (3) every 3 seconds
> > (4) when a checkpoint occurs
> > (5) when a commit occurs.
> >
> > Therefore, see if any of these could be the problem. It's easy to
> > check #s 4 and 3.
> >
> > As Kirti suggested, the problem could be due to the redo logs being
> > on a busy disk, or even a slow one.
> >
> > HTH.
> >
> > Arup
> >   - Original Message -
> >   From: Deshpande, Kirti
> >   To: Multiple recipients of list ORACLE-L
> >   Sent: Thursday, March 13, 2003 8:13 PM
> >   Subject: RE: log buffer space
> >
> >
> >   Increasing log_buffer size is an option, if it is really small.
> >   I would also check if the redo logs are on a busy disk. If so, try
> > moving those (or other busy data files on the same disk) to other
> > not-so-busy disks.
> >
> >   - Kirti
>
>
> =
> Have a nice day !!
> 
> Best Regards,
> K Gopalakrishnan,
> Bangalore, INDIA.
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: K Gopalakrishnan
>   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: AK
  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).

Re: log buffer space

[AK]

Are there any equations which can say log buffer is 
small or large ? I mean how to find the proper size of log buffer .
 
-ak

  - Original Message - 
  From: 
  Deshpande, Kirti 
  To: Multiple recipients of list ORACLE-L 
  
  Sent: Thursday, March 13, 2003 5:13 
  PM
  Subject: RE: log buffer space
  
  Increasing log_buffer size is an option, if it is really small. 
  
  I 
  would also check if the redo logs are on a busy disk. If so, try moving those 
  (or other busy data files on the same disk) to other not-so-busy 
  disks. 
   
  - 
  Kirti 
   
  -Original Message-From: [EMAIL PROTECTED] 
  [mailto:[EMAIL PROTECTED]Sent: Thursday, March 13, 2003 4:49 
  PMTo: Multiple recipients of list ORACLE-LSubject: log 
  buffer space
  
I am finding tons of  "log buffer space" 
waits in 10046 output . Does it necessarily means I should look for resizing 
log_buffer ? What else can be done or looked at to reduce these waits 
.
 
Thanks,
ak
 

RE: log buffer space

[Deshpande, Kirti]

What's the size of your log buffer, and the redo log file? 
Do you see any errors/messages in alert.log file that are related to 'checkpoints' or 
'log switching'? 

- Kirti 

-Original Message-
Sent: Friday, March 14, 2003 10:14 AM
To: Multiple recipients of list ORACLE-L


Do you guys think , adding more log file can help ? I think it should not ,
cuz any way logwriter is going to write in one datafile at a time , correct
?

-ak


- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 4:32 AM


> Arup:
>
> 
> The second condition is not quite true. It is 2/3 full in the current
> versions.
> 
>
> It is very easy to test with the event 10046^8.
>
> KG
>
>
> --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > AK,
> >
> > If the log buffer is at least 4MB, then increasing it will not help,
> > rather it may hurt. The log buffer is flushed when any of the the
> > follwoing occur
> > (i) 1 MB is filled up
> > (2) 1/3rd is filled up
> > (3) every 3 seconds
> > (4) when a checkpoint occurs
> > (5) when a commit occurs.
> >
> > Therefore, see if any of these could be the problem. It's easy to
> > check #s 4 and 3.
> >
> > As Kirti suggested, the problem could be due to the redo logs being
> > on a busy disk, or even a slow one.
> >
> > HTH.
> >
> > Arup
> >   - Original Message -
> >   From: Deshpande, Kirti
> >   To: Multiple recipients of list ORACLE-L
> >   Sent: Thursday, March 13, 2003 8:13 PM
> >   Subject: RE: log buffer space
> >
> >
> >   Increasing log_buffer size is an option, if it is really small.
> >   I would also check if the redo logs are on a busy disk. If so, try
> > moving those (or other busy data files on the same disk) to other
> > not-so-busy disks.
> >
> >   - Kirti
>
>

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Deshpande, Kirti
  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).

RE: log buffer space

[DENNIS WILLIAMS]

Add one more condition: 
   New in Oracle 9i, it will write when 1 meg is reached, so the 1/3
criteria is never reached if you use a big buffer.

Dennis Williams
DBA, 40%OCP, 100% DBA
Lifetouch, Inc.
[EMAIL PROTECTED] 


-Original Message-
Sent: Friday, March 14, 2003 8:59 AM
To: Multiple recipients of list ORACLE-L


KG,

Thanks for the response. Just for my curiosity, is it documented somewhere
that the log buffer if flushed when 2/3rd full? From the Manual
/server.920/a96524/c09procs.htm#3158 (please check the URL in OTN, the first
part is not complete), here is an excerpt


LGWR writes one contiguous portion of the buffer to disk. LGWR writes:
  a.. A commit record when a user process commits a transaction
  b.. Redo log buffers
a.. Every three seconds
b.. When the redo log buffer is one-third full
c.. When a DBWn process writes modified buffers to disk, if necessary



At least this was the behavior I tested in 8.1.7; although I have not tested
in 9i. This has also been stated by several Oracle Support Analysts.

Thanks.

Arup Nanda

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 7:32 AM


> Arup:
>
> 
> The second condition is not quite true. It is 2/3 full in the current
> versions.
> 
>
> It is very easy to test with the event 10046^8.
>
> KG
>
>
> --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > AK,
> >
> > If the log buffer is at least 4MB, then increasing it will not help,
> > rather it may hurt. The log buffer is flushed when any of the the
> > follwoing occur
> > (i) 1 MB is filled up
> > (2) 1/3rd is filled up
> > (3) every 3 seconds
> > (4) when a checkpoint occurs
> > (5) when a commit occurs.
> >
> > Therefore, see if any of these could be the problem. It's easy to
> > check #s 4 and 3.
> >
> > As Kirti suggested, the problem could be due to the redo logs being
> > on a busy disk, or even a slow one.
> >
> > HTH.
> >
> > Arup
> >   - Original Message -
> >   From: Deshpande, Kirti
> >   To: Multiple recipients of list ORACLE-L
> >   Sent: Thursday, March 13, 2003 8:13 PM
> >   Subject: RE: log buffer space
> >
> >
> >   Increasing log_buffer size is an option, if it is really small.
> >   I would also check if the redo logs are on a busy disk. If so, try
> > moving those (or other busy data files on the same disk) to other
> > not-so-busy disks.
> >
> >   - Kirti
>
>
> =
> Have a nice day !!
> 
> Best Regards,
> K Gopalakrishnan,
> Bangalore, INDIA.
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: K Gopalakrishnan
>   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: Arup Nanda
  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).

Re: log buffer space

[AK]

Do you guys think , adding more log file can help ? I think it should not ,
cuz any way logwriter is going to write in one datafile at a time , correct
?

-ak


- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 4:32 AM


> Arup:
>
> 
> The second condition is not quite true. It is 2/3 full in the current
> versions.
> 
>
> It is very easy to test with the event 10046^8.
>
> KG
>
>
> --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > AK,
> >
> > If the log buffer is at least 4MB, then increasing it will not help,
> > rather it may hurt. The log buffer is flushed when any of the the
> > follwoing occur
> > (i) 1 MB is filled up
> > (2) 1/3rd is filled up
> > (3) every 3 seconds
> > (4) when a checkpoint occurs
> > (5) when a commit occurs.
> >
> > Therefore, see if any of these could be the problem. It's easy to
> > check #s 4 and 3.
> >
> > As Kirti suggested, the problem could be due to the redo logs being
> > on a busy disk, or even a slow one.
> >
> > HTH.
> >
> > Arup
> >   - Original Message -
> >   From: Deshpande, Kirti
> >   To: Multiple recipients of list ORACLE-L
> >   Sent: Thursday, March 13, 2003 8:13 PM
> >   Subject: RE: log buffer space
> >
> >
> >   Increasing log_buffer size is an option, if it is really small.
> >   I would also check if the redo logs are on a busy disk. If so, try
> > moving those (or other busy data files on the same disk) to other
> > not-so-busy disks.
> >
> >   - Kirti
>
>
> =
> Have a nice day !!
> 
> Best Regards,
> K Gopalakrishnan,
> Bangalore, INDIA.
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: K Gopalakrishnan
>   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: AK
  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).

Re: log buffer space

[Arup Nanda]

KG,

Thanks for the response. Just for my curiosity, is it documented somewhere
that the log buffer if flushed when 2/3rd full? From the Manual
/server.920/a96524/c09procs.htm#3158 (please check the URL in OTN, the first
part is not complete), here is an excerpt


LGWR writes one contiguous portion of the buffer to disk. LGWR writes:
  a.. A commit record when a user process commits a transaction
  b.. Redo log buffers
a.. Every three seconds
b.. When the redo log buffer is one-third full
c.. When a DBWn process writes modified buffers to disk, if necessary



At least this was the behavior I tested in 8.1.7; although I have not tested
in 9i. This has also been stated by several Oracle Support Analysts.

Thanks.

Arup Nanda

- Original Message -
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Friday, March 14, 2003 7:32 AM


> Arup:
>
> 
> The second condition is not quite true. It is 2/3 full in the current
> versions.
> 
>
> It is very easy to test with the event 10046^8.
>
> KG
>
>
> --- Arup Nanda <[EMAIL PROTECTED]> wrote:
> > AK,
> >
> > If the log buffer is at least 4MB, then increasing it will not help,
> > rather it may hurt. The log buffer is flushed when any of the the
> > follwoing occur
> > (i) 1 MB is filled up
> > (2) 1/3rd is filled up
> > (3) every 3 seconds
> > (4) when a checkpoint occurs
> > (5) when a commit occurs.
> >
> > Therefore, see if any of these could be the problem. It's easy to
> > check #s 4 and 3.
> >
> > As Kirti suggested, the problem could be due to the redo logs being
> > on a busy disk, or even a slow one.
> >
> > HTH.
> >
> > Arup
> >   - Original Message -
> >   From: Deshpande, Kirti
> >   To: Multiple recipients of list ORACLE-L
> >   Sent: Thursday, March 13, 2003 8:13 PM
> >   Subject: RE: log buffer space
> >
> >
> >   Increasing log_buffer size is an option, if it is really small.
> >   I would also check if the redo logs are on a busy disk. If so, try
> > moving those (or other busy data files on the same disk) to other
> > not-so-busy disks.
> >
> >   - Kirti
>
>
> =
> Have a nice day !!
> 
> Best Regards,
> K Gopalakrishnan,
> Bangalore, INDIA.
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: K Gopalakrishnan
>   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: Arup Nanda
  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).

Re: log buffer space

[K Gopalakrishnan]

Arup:


The second condition is not quite true. It is 2/3 full in the current
versions. 


It is very easy to test with the event 10046^8. 

KG


--- Arup Nanda <[EMAIL PROTECTED]> wrote:
> AK,
> 
> If the log buffer is at least 4MB, then increasing it will not help,
> rather it may hurt. The log buffer is flushed when any of the the
> follwoing occur
> (i) 1 MB is filled up
> (2) 1/3rd is filled up
> (3) every 3 seconds
> (4) when a checkpoint occurs
> (5) when a commit occurs.
> 
> Therefore, see if any of these could be the problem. It's easy to
> check #s 4 and 3. 
> 
> As Kirti suggested, the problem could be due to the redo logs being
> on a busy disk, or even a slow one.
> 
> HTH.
> 
> Arup
>   - Original Message - 
>   From: Deshpande, Kirti 
>   To: Multiple recipients of list ORACLE-L 
>   Sent: Thursday, March 13, 2003 8:13 PM
>   Subject: RE: log buffer space
> 
> 
>   Increasing log_buffer size is an option, if it is really small. 
>   I would also check if the redo logs are on a busy disk. If so, try
> moving those (or other busy data files on the same disk) to other
> not-so-busy disks. 
> 
>   - Kirti 


=
Have a nice day !!

Best Regards,
K Gopalakrishnan,
Bangalore, INDIA.
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: K Gopalakrishnan
  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).

Re: log buffer space

[Arup Nanda]

AK,
 
If the log buffer is at least 4MB, then increasing 
it will not help, rather it may hurt. The log buffer is flushed when any of the 
the follwoing occur
(i) 1 MB is filled up
(2) 1/3rd is filled up
(3) every 3 seconds
(4) when a checkpoint occurs
(5) when a commit occurs.
 
Therefore, see if any of these could be the 
problem. It's easy to check #s 4 and 3. 
 
As Kirti suggested, the problem could be due to the 
redo logs being on a busy disk, or even a slow one.
 
HTH.
 
Arup

  - Original Message - 
  From: 
  Deshpande, Kirti 
  To: Multiple recipients of list ORACLE-L 
  
  Sent: Thursday, March 13, 2003 8:13 
  PM
  Subject: RE: log buffer space
  
  Increasing log_buffer size is an option, if it is really small. 
  
  I 
  would also check if the redo logs are on a busy disk. If so, try moving those 
  (or other busy data files on the same disk) to other not-so-busy 
  disks. 
   
  - 
  Kirti 
   
  -Original Message-From: [EMAIL PROTECTED] 
  [mailto:[EMAIL PROTECTED]Sent: Thursday, March 13, 2003 4:49 
  PMTo: Multiple recipients of list ORACLE-LSubject: log 
  buffer space
  
I am finding tons of  "log buffer space" 
waits in 10046 output . Does it necessarily means I should look for resizing 
log_buffer ? What else can be done or looked at to reduce these waits 
.
 
Thanks,
ak
 

RE: log buffer space

[Deshpande, Kirti]

Increasing log_buffer size is an option, if it is really small. 

I 
would also check if the redo logs are on a busy disk. If so, try moving those 
(or other busy data files on the same disk) to other not-so-busy 
disks. 
 
- 
Kirti 
 
-Original Message-From: [EMAIL PROTECTED] 
[mailto:[EMAIL PROTECTED]Sent: Thursday, March 13, 2003 4:49 
PMTo: Multiple recipients of list ORACLE-LSubject: log 
buffer space

  I am finding tons of  "log buffer space" 
  waits in 10046 output . Does it necessarily means I should look for resizing 
  log_buffer ? What else can be done or looked at to reduce these waits 
  .
   
  Thanks,
  ak
   

log buffer space

[AK]

I am finding tons of  "log buffer space" waits 
in 10046 output . Does it necessarily means I should look for resizing 
log_buffer ? What else can be done or looked at to reduce these waits 
.
 
Thanks,
ak