log_checkpoint_timeout new meaning in 8i

From: Koivu, Lisa <lkoivu_at_qode.com>
Date: Thu, 4 Jan 2001 10:18:58 -0500
Message-Id: <10731.125718@fatcity.com>

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hello all,

I've got LOG_CHECKPOINT_TIMEOUT set to 1800 (30 minutes) in one of my databases. I also have LOG_CHECKPOINTS_TO_ALERT set to true. However, every morning I look at the archive logs and I see that 1. the logs haven't switched since the nightly batch quit and 2. there are no checkpoints in the alert log since the log switch. This makes me a little nervous.

It seems that LOG_CHECKPOINT_TIMEOUT is not working. However, I find this on metalink that kind of explains it.

The parameter log_checkpoint_timeout has been re-interpreted. In prior releases, every log_checkpoint_timeout seconds, Oracle started an interval checkpoint. Starting with Oracle 8.1, log_checkpoint_timeout will be interpreted to mean that the incremental checkpoint should be at the log position where the tail of the log was log_checkpoint_timeout seconds ago. In other words, the incremental checkpoint should lag the tail of the log by no more than log_checkpoint_timeout seconds worth of redo.

I don't quite understand. Can someone paraphrase this? Does this mean that every LOG_CHECKPOINT_TIMEOUT seconds it makes sure that there is no redo that hasn't been written to disk that is more than LOG_CHECKPOINT_TIMEOUT seconds old? In other words, it checks to see if a checkpoint is necessary instead of just doing it?

Thanks

Lisa Rutland Koivu
Oracle Database Administrator
Qode.com
4850 North State Road 7
Suite G104
Fort Lauderdale, FL 33319

V: 954.484.3191, x174
F: 954.484.2933 
C: 954.658.5849

http://www.qode.com

"The information contained herein does not express the opinion or position of Qode.com and cannot be attributed to or made binding upon Qode.com."

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hello all, 


I've got LOG_CHECKPOINT_TIMEOUT set to =
1800 (30 minutes) in one of my databases.  I also have = LOG_CHECKPOINTS_TO_ALERT set to true.  However, every morning I = look at the archive logs and I see that 1. the logs haven't switched = since the nightly batch quit and 2. there are no checkpoints in the = alert log since the log switch.  This makes me a little nervous. =


 It seems that =
LOG_CHECKPOINT_TIMEOUT is not working.  However, I find this on = metalink that kind of explains it. 


The parameter log_checkpoint_timeout =
has been re-interpreted. In prior releases, every = log_checkpoint_timeout seconds, Oracle started an interval checkpoint. = Starting with Oracle 8.1, log_checkpoint_timeout will be interpreted to = mean that the incremental checkpoint should be at the log position = where the tail of the log was log_checkpoint_timeout seconds ago. In = other words, the incremental checkpoint should lag the tail of the = log by no more than log_checkpoint_timeout seconds worth of redo. =


I don't quite understand.  Can =
someone paraphrase this?  Does this mean that every = LOG_CHECKPOINT_TIMEOUT seconds it makes sure that there is no redo that = hasn't been written to disk that is more than LOG_CHECKPOINT_TIMEOUT = seconds old?  In other words, it checks to see if a checkpoint is = necessary instead of just doing it?

Thanks


Lisa Rutland Koivu
 Oracle Database Administrator
 Qode.com
 4850 North State Road 7
 Suite G104
 Fort Lauderdale, FL  =
33319


V: 954.484.3191, x174
 F: 954.484.2933 
 C: 954.658.5849
 <A HREF=3D"http://www.qode.com" =
TARGET=3D"_blank">http://www.qode.com</A>


"The =
information contained herein does not express the opinion or position = of Qode.com and cannot be attributed to or made binding upon = Received on Thu Jan 04 2001 - 09:18:58 CST