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Hi Mates,
My query is about checkpoints. Ia m running oracle 7.3.4 in Sun Solaris. According to oracle checkpotints occures primiraily when (While database working normally)
1. When a logswitch occures
2. based on the parameter value LOG_CHECKPOINT_INTERVAL
3. based on the parameter value LOG_CHECKPOINT_TIMEOUT
Well, now my redo log size is 100MB
LOG_CHECKPOINT_TIMEOUT = 0
LOG_CHECKPOINT_INTERVAL=20000000 (Which is grater than the size of the redolog file)
Normally, there are 15 - 20 arcgive log files created every day. ( 15 - 20 logswitches). Bur I found the value of checkpoints is 700 for today. LOG_CHECKPOINT_TIMEOUT=0, ie Time based checkpoint is disabled. LOG_CHECKPOINT_INTERVAL is higher than redo log size. Again 15 -20 logswitches.
My question, What is the reason for this many number of checkpoints.??
Please hel me.
Regards
Thomas
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How did you find the checkpoint number? and what is your redo log buffer size?
-nagarjuna
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Is there any possibility that following commands are being issued manually or by some jobs..
ALTER SYSTEM SWITCH LOGFILE;
or
ALTER SYSTEM CHECKPOINT;
Sanjay
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quote
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nagarjuna How did you find the checkpoint number? and what is your redo log buffer size?
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u can find checkpoint number from the following query
select distinct checkpoint_change# from v$datafile;
we can get from check point details from alert log file also if u have set the
LOG_CHECKPOINTS_TO_ALERT = TRUE .
just count how many check points are happening in a single day .
siva prakash
DBA
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checkpoint from log switch and LOG_CHECKPOINTS_TO_ALERT are so called official checkpoints or interval checkpoints, internally Oracle performs many incremental checkpoints (from Oracle 8.x) which is quite difficult to follow (at least I dont know where are these incrmenetal checkpoints recorded)
Only way I know if incremental checkpoint has occured is by looking v$sysstat DBWR checkpoint buffers written
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checkpoints
Hi all
Thanks for the replies.
Well, I think my calculation was wrong. I used the value DBWR checkpoints in t V$SYSSTAT to calculate. But later I understand that these are the number of times DBWR requested for a checkpoint, not an actual checkpoint.
According to Mr. Pando, These are the incremental check points. I have no idea about that..!
I appreciate your replies.
Regards
Thomas
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hey note i said from Oracle 8.x
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checkpoints
Hi Mates
Checkpoints still not ends here!
Now I found big values (compared to the number fo checkpoints) in 'DBWR checkpoints' in v$sysstat. These are the requests by the DBWR for a checkpoint. Why the DBWR is requesting for so many checkcpoints? Is this high value is a sysmptom of a problem? How DBWR decide to request for a check point? If this is a problem, how can I correct it?
Thanks
Thomas P S
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