Message-Id: <10731.125718@fatcity.com> From: "Koivu, Lisa" Date: Thu, 4 Jan 2001 10:18:58 -0500 Subject: log_checkpoint_timeout new meaning in 8i This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C07661.A8E7D0E6 Content-Type: text/plain; charset="iso-8859-1" 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." ------_=_NextPart_001_01C07661.A8E7D0E6 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable log_checkpoint_timeout new meaning in 8i

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 =