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Hi All,
I am getting error
Checkpoint not complete.
My redo config is
4 Groups
2 members in each group
size of redo files 20 MB
OS Block Size 2048
log_checkpoin_interval = 300000
log_checkpoint_timeout = 0
i understand that checkpint occur only at switching logs if
log_checkpoint_interval * size of OS block > actual redo lg file size
and in my case it is like that only, right ?
so what should i do and let me know what is the harm of this error.
HELP ME !!!!
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The Time has come ....
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Your database may be experiencing many INSERTs or LONG/RAW activity. You might have to tune your log buffer size.
Consider a scenario when the redo log buffer is 1/3 full or the user commits. Now LGWR has to write to an available online redolog. If such a scenario occurs during checkpoint, the user has to wait for log switch to occur before checkpoint is complete and next redo log is available.
You can review V$SYSSTAT:
SELECT a.VALUE / DECODE(b.VALUE, 0, 1, b.VALUE)
FROM V$SYSSTAT a, V$SYSSTAT b
WHERE a.NAME = 'redo size' AND b.NAME = 'user commits';
This provides the average number redo records per commit. Now you must determine the average number of commits per second and multiply it by the average number redo records per commit (calculated above). This provides the max log buffers to setup.
You can then monitor the event 'Log file switch (checkpoint incomplete)'.
so what should i do and let me know what is the harm of this error.
Performance degrades. Users keep waiting for a log switch because the session cannot wrap into the next log. Wrapping cannot be performed because the checkpoint for that log has not completed.
No way I can claim that at present. But the day is not far off.....
[Edited by Raminder on 11-09-2001 at 01:41 AM]
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checkpoint error
raminder - i'll what u hv said and post the reply here. guide me then.
on checking the alert file again i found that though this is ot occuring very frequently, but still i feel that this need attention.
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The Time has come ....
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further rinfo
Hi,
avg. redo per commit is 38833.7869 (i hope it is correct).
how to find avg. no of commits per second.
i think i hv to divide this value by time that a redolog file takes to fill.
like in my case avg. is 11 min. i.e. 660 sec
so if i m correct avg. no of commits 38833.7869 / 660
= 25630299.354 bytes (is it ?).
i hv log_buffers = 1048576
now what ?
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The Time has come ....
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your LOG_CHECKPOINT_INTERVAL(300000) is to small for an interval of a redo log size of 20M(20000000). You've forces to have a checkpoint of every 300000 volume of bytes out of 20000000 written to the redo logs from the log buffer. This phase is fast. I suggest you increase your LOG_CHECKPOINT_INTERVAL to 20000001 or 99999999.
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well 300000 os block is 60mb so it´s ok
paste a few lines from alert log which you see this message might help
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Hi Pando,
So we consider here the O.S. block size which is 2048? Ok.
Can you please tell me or refer me a url that discusses this matter with emphasis of the consideration of the O.S. block size. thanks a lot.
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300000 is OK altough I prefer 9999999 :-)
I wonder why he/she use 2K for a block size. I would say that even 4 is small nowardays.
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Originally posted by julian
I wonder why he/she use 2K for a block size. I would say that even 4 is small nowardays.
2K is OS block size, which is quite usual nowadays. I belive you had DB block size in mind with your remark, no?
[Edited by jmodic on 11-09-2001 at 08:29 AM]
Jurij Modic
ASCII a stupid question, get a stupid ANSI
24 hours in a day .... 24 beer in a case .... coincidence?
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Right, I have overlooked this one, you have the eyes of an eagle :-)
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