Hi Oracle-List, my question is based on the following statement in the 11gR2 documentation: ====================== Thread checkpoints occur in the following situations: <...> Online redo log switch AND: An incremental checkpoint is a type of thread checkpoint partly intended to avoid writing large numbers of blocks at online redo log switches. DBWn checks at least every three seconds to determine whether it has work to do. When DBWn writes dirty buffers, it advances the checkpoint position, causing CKPT to write the checkpoint position to the control file, but not to the data file headers. (http://docs.oracle.com/cd/E11882_01/server.112/e25789/startup.htm#CNCPT89043) ====================== My observation in Redo Log confirms: ====================== Tue Sep 11 10:05:26 2012 Beginning log switch checkpoint up to RBA [0x9d3c.2.10], SCN: 111597554694 Thread 1 advanced to log sequence 40252 (LGWR switch) Current log# 18 seq# 40252 mem# 0: +ORADATA/devee05/onlinelog/group_18.289.776430937 Current log# 18 seq# 40252 mem# 1: +ORAFRA/devee05/onlinelog/group_18.617.776430941 Tue Sep 11 10:05:27 2012 Archived Log entry 40166 added for thread 1 sequence 40251 ID 0x70a7206d dest 1: <end of alert log> ====================== This looks as if there is a checkpoint triggered at the very time of the redo log switch. But if I check v$database, I can't see any checkpoint progress. ====================== SYSDATE CURRENT_SCN CHECKPOINT_CHANGE# CONTROLFILE_CHANGE# ------------------------- ---------------------- ---------------------- ---------------------- 11.09.2012 10:07:40 111597621204 111597358540 111597607427 ====================== After a while, I see in the alert log: ====================== Tue Sep 11 10:10:19 2012 Completed checkpoint up to RBA [0x9d39.2.10], SCN: 111597545203 Completed checkpoint up to RBA [0x9d3a.2.10], SCN: 111597548331 Completed checkpoint up to RBA [0x9d3b.2.10], SCN: 111597551671 Completed checkpoint up to RBA [0x9d3c.2.10], SCN: 111597554694 ====================== And my select confirms: ====================== SYSDATE CURRENT_SCN CHECKPOINT_CHANGE# CONTROLFILE_CHANGE# ------------------------- ---------------------- ---------------------- ---------------------- 11.09.2012 10:12:03 111597713033 111597554694 111597709213 ====================== So far, so good: Now I know that the CHECKPOINT_CHANGE# is identical to the alert.log entry. But my final question is: How can I monitor the progress of the incremental checkpoint? Because my impression (not more) is, that CHECKPOINT_CHANGE# jumps as soon as the checkpoint is complete. Thank you very much Martin Klier -- Usn's IT Blog for Linux, Oracle, Asterisk http://www.usn-it.de -- //www.freelists.org/webpage/oracle-l