Skip to Content
0
Former Member
Feb 11, 2010 at 12:49 PM

Import SCAs to a DI results in "checkpoint not complete" in alert log

38 Views

Hello everybody,<br>

<br>

I am setting up a new shared NW 7.11 DI system here. Right now I am doing some test imports.<br>

<br>

The sap system ist running on a SLES 10 SP2 server with oracle 10.2.0.4 as DB. 4 CPUs 16GB RAM <br>

<br>

Oh yes, maybe I should say that I am not a true oracle expert, I know a thing or aonther but...<br>

<br>

When doing the import in CMS, naturally, a lot of data is writen to the DB. So I checked the alert log when importing, to see how the redo log groups and archiving is getting along with the import.<br>

<br>

I see quit some "checkpoint not complete" messages in the alert log. Which usualy is not a good thing when happening very often.<br>

<br>

So I did what usually is recommended when this happens. I increased the number of redo log groups from 3 to 6 to 10 and made some test with increasing the number of dbwr processes. <br>

<br>

After sepnding 2 days testing and reading documentation. I only can say that all the measures I have taken did not make any real difference at all. The import took round about 5 minutes with 2 dbwr and 6 redo log groups doing 12 logswitches and and it had the same result with 4 dbwr process and 10 redo log groups.<br>

<br>

5 minute is an acceptable time for this import, but I don#t understnd the log entries.<br>

<br>

I am note sure if this alert log entries make any difference at all. i realsised the first time i saw them that oracle say a checkpoint is not complete and, sometime in the same secound, it makes the checkpoing and frees a redo log group. Looks like this:<br>

<br>

Thu Feb 11 12:20:21 2010<br>

Thread 1 cannot allocate new log, sequence 462<br>

Checkpoint not complete<br>

Current log# 3 seq# 461 mem# 0: /oracle/C11/origlogA/log_g13m1.dbf<br>

Current log# 3 seq# 461 mem# 1: /oracle/C11I/mirrlogA/log_g13m2.dbf<br>

Thu Feb 11 12:20:23 2010<br>

Completed checkpoint up to RBA [0x1c5.2.10], SCN: 5932669<br>

Thu Feb 11 12:20:23 2010<br>

Beginning log switch checkpoint up to RBA [0x1ce.2.10], SCN: 5949907<br>

Thu Feb 11 12:20:23 2010<br>

Thread 1 advanced to log sequence 462 (LGWR switch)<br>

Current log# 7 seq# 462 mem# 0: /oracle/C11I/origlogA/log_g17m1.dbf<br>

Current log# 7 seq# 462 mem# 1: /oracle/C11/mirrlogA/log_g17m2.dbf<br>

<br>

So I understand why I don't see a big performance impact when increasing dbwr and log groups, becuase the checkpint not complete wait time is quit short. But I do not really understand why oracel is not freeing the log groups sooner. it seems not to be a problem after all when it is absolutely required. <br>

<br>

I read about the new feature that oracle can adjust the chckpoint intraval to meet FAST_START_MTTR_TARGET but this is not set in my case..<br>

<br>

Thu Feb 11 10:23:36 2010<br>

MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set<br>

<br>

Can any of you experts out there give me some advice or better an explaination what this entrys mean or are they benign and can be ignored after all? I almost guess so because in Enterprise Manger nothing is shown in alert log warnings etc.<br>

<br>

Looking forward hearing fron you<br>

Jan<br>

Edited by: Jan Benkert on Feb 11, 2010 1:55 PM